QOF  0.8.0
Data Structures | Files | Defines | Typedefs | Functions
Date: 64bit UTC date handling.
Time: 64bit UTC Time handling.

Data Structures

struct  QofDate_s
 Full range replacement for struct tm. More...

Files

file  qofdate.h
 

64bit Date handling routines


Defines

#define MAX_DATE_LENGTH   41
 The maximum length of a string used for or created by dates.
#define MAX_DATE_BUFFER   256
 The maximum length of a QofDate buffer.
#define SECS_PER_DAY   86400
#define SECS_PER_HOUR   3600
#define QOF_MOD_DATE   "qof-dates"
#define qof_date_isleap(year)   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
#define QOF_UTC_DATE_FORMAT   "%Y-%m-%dT%H:%M:%SZ"
 UTC date format string.
#define QOF_HOUR_TO_SEC(x)   (x * SECS_PER_HOUR)
#define QOF_MIN_TO_SEC(x)   (x * 60)
#define QOF_DAYS_TO_SEC(x)   (x * SECS_PER_DAY)

Typedefs

typedef struct QofDate_s QofDate
 Full range replacement for struct tm.
typedef gint QofDateFormat

Functions

void qof_date_init (void)
 initialise the QofDate tables
void qof_date_close (void)
 close down the QofDate tables

Default QofDate formats

#define QOF_DATE_FORMAT_US   1
 Continental US default. "%m/%d/%Y".
#define QOF_DATE_FORMAT_UK   2
 United Kingdom default. "%d/%m/%Y".
#define QOF_DATE_FORMAT_CE   3
 Contintental European default. "%d.%m.%Y".
#define QOF_DATE_FORMAT_ISO   4
 Short ISO form. "%F".
#define QOF_DATE_FORMAT_UTC   5
 QOF UTC format, xsd:date compatible. QOF_UTC_DATE_FORMAT "%Y-%m-%dT%H:%M:%SZ".
#define QOF_DATE_FORMAT_ISO8601   6
#define QOF_DATE_FORMAT_LOCALE   7
 GNU locale default. "%x".
#define QOF_DATE_FORMAT_CUSTOM   8
 Date and time for the current locale "%c".
#define DATE_FORMAT_LAST   QOF_DATE_FORMAT_CUSTOM

QofDateFormat - standardised date formats

To simplify usage of strftime and strptime (especially checking error states), QofDate uses a set of standard date formats. You can also register your own format strings as long as they are strftime compatible.

see also QofDate and locales.

gboolean qof_date_format_add (const gchar *str, QofDateFormat *identifier)
 Add a specific strftime compatible string as a new QofDateFormat.
const gchar * qof_date_format_to_name (QofDateFormat format)
 Retrieve the shorthand name for the selected date format.
QofDateFormat qof_date_format_from_name (const gchar *name)
 Returns the default date format for a known shorthand name.
gboolean qof_date_format_set_name (const gchar *name, QofDateFormat format)
 Set a shorthand name for a custom date format.
QofDateFormat qof_date_format_get_current (void)
 returns the current date format.
gboolean qof_date_format_set_current (QofDateFormat df)
 Selects one registered date format as the current default.
const gchar * qof_date_format_get_format (QofDateFormat df)
 Retrieve the strftime format string for a registered date format.
gchar qof_date_format_get_date_separator (QofDateFormat df)
 Return the field separator for the current date format.
gboolean qof_date_format_set_date_separator (const gchar sep, QofDateFormat df)
 Set a locale-specific separator.

QofDate handlers

QofDateqof_date_new (void)
QofDateqof_date_get_current (void)
QofDateqof_date_new_dmy (gint day, gint month, gint64 year)
void qof_date_free (QofDate *date)
QofTimeqof_date_time_difference (const QofDate *date1, const QofDate *date2)
gboolean qof_date_is_last_mday (const QofDate *qd)
gboolean qof_date_addmonths (QofDate *qd, gint months, gboolean track_last_day)
gboolean qof_date_equal (const QofDate *d1, const QofDate *d2)
gint qof_date_compare (const QofDate *d1, const QofDate *d2)
gboolean qof_date_valid (QofDate *date)
 Validate a QofDate.
guint16 qof_date_get_yday (gint mday, gint month, gint64 year)
guint8 qof_date_get_mday (gint month, gint64 year)

Conversion handlers for QofDate

QofDateqof_date_from_qtime (const QofTime *qt)
QofTimeqof_date_to_qtime (const QofDate *qd)
QofDateqof_date_from_struct_tm (const struct tm *stm)
 Convert a struct tm to a QofDate.
gboolean qof_date_to_struct_tm (const QofDate *qt, struct tm *stm, glong *nanosecs)
 Convert a QofDate to a struct tm.
gboolean qof_date_to_gdate (const QofDate *qd, GDate *gd)
 Convert a QofDate to a GDate.
QofDateqof_date_from_gdate (const GDate *gd)
 Create a QofDate from a GDate.

Manipulate QofTime as a date

Shorthand routines to modify a QofTime using date-type values, instead of having to always use seconds.

gboolean qof_date_adddays (QofDate *qd, gint days)
 Add a number of days to a QofDate and normalise.
gboolean qof_date_set_day_end (QofDate *qd)
gboolean qof_date_set_day_start (QofDate *qd)
gboolean qof_date_set_day_middle (QofDate *qd)

Date Printing/Scanning functions

QofDate supports a wider range of dates than either strftime or GDate and supports all non-locale-specific strftime format specifiers over the full range of QofDate.

Note:
Locale-specific formats cannot be extended to the full range of QofDate dates because the locale data for these formats is only available to the underlying strftime implementation. The formats affected are those involving the E and O modifiers and other format specifiers that use the current locale. e.g. Japanese Emperor reigns, local numeric specifiers, translated days of the week / month etc. If these are used, only dates within the range of the locale-sensitive strftime on that platform can be supported (either inside or outside QofDate).

The full list of affected format specifiers is:

'a', 'A', 'b', 'h', 'B', 'c', 'C', 'x', 'p', 'P', 'r', 'X', 'E', 'O'.
 

QofDate will attempt to fallback to a usable format if the date is out of range of the underlying strftime. e.g. QOF_DATE_FORMAT_UTC, QOF_DATE_FORMAT_UK, QOF_DATE_FORMAT_US, QOF_DATE_FORMAT_CE or QOF_DATE_FORMAT_ISO.

Note:
It is not particularly sensible to write locale-sensitive date strings to any kind of permanent storage. Locale-specific format specifiers should only be used for displaying dates to the user.

For more information, see QofDate and locales.

  • Scanning: Convert a timestamp into a QofTime*
    1. To scan a string yourself, use qof_date_format_get_format to get the format to pass to strptime or use g_date_set_parse
    2. To scan a stamp created with a registered date format, use qof_date_parse
gchar * qof_date_print (const QofDate *date, QofDateFormat df)
 Convert a QofDate to a timestamp according to the specified date format.
QofDateqof_date_parse (const gchar *str, QofDateFormat df)
 Convert a timestamp to a QofTime.

Detailed Description

All dates in QOF use Universal Coordinated Time, (UTC), wrapped to allow representation of dates before the epoch.

localtime is available via GDate but there are limitations.

  1. The GDate data structure represents a day between January 1, Year 1, and sometime a few thousand years in the future, not the full range of QofTime.
  2. Right now GDate will go to the year 65535 or so, but g_date_set_parse() only parses up to the year 8000 or so - just count on "a few thousand".
  3. g_date_strftime only deals with date related formats, results of using time formats is undefined.

A QofDateEntry is one a collection of formats for handling dates, including common defaults. New entries need to be registered using qof_date_add_format before being used to print or scan strings containing dates.

Todo:
Add support for customised handlers for added formats.

A QofDate is theoretically able to go forward to the year 292,471,206,707 AD and back to the year 292,471,206,708 BC. Whether such dates actually exist is outside the scope of this documentation.

Note:
Time moves at a constant rate, dates do not. Dates are inherently tied to the rotation of the Earth and that rotation is slowing down, causing the need for leapseconds. The incidence of leapseconds cannot be accurately predicted and dates far into the future may be out by a number of seconds. This is important if future dates are based around the start (or end) of a particular day - when those dates come to be viewed as the past, the actual day calculated from the number of seconds may differ to the day originally calculated. When using future dates, avoid using dates at the start or end of a particular day.
Since:
v0.7.0

Define Documentation

#define DATE_FORMAT_LAST   QOF_DATE_FORMAT_CUSTOM

New identifiers must be larger than this.

Definition at line 322 of file qofdate.h.

#define MAX_DATE_BUFFER   256

The maximum length of a QofDate buffer.

Todo:
rationalise with MAX_DATE_LENGTH

Definition at line 92 of file qofdate.h.

#define MAX_DATE_LENGTH   41

The maximum length of a string used for or created by dates.

When setting a custom QofDateFormat, neither the format string itself nor any date string created from that format is allowed to exceed this length.

Definition at line 87 of file qofdate.h.

#define QOF_DATE_FORMAT_CE   3

Contintental European default. "%d.%m.%Y".

9th May 2006 == 09.05.2006

Definition at line 263 of file qofdate.h.

#define QOF_DATE_FORMAT_CUSTOM   8

Date and time for the current locale "%c".

QOF_DATE_FORMAT_LOCALE and QOF_DATE_FORMAT_CUSTOM are only suitable for date / time display - storing these values in any kind of file is a recipe for disaster as the exact format can be affected by environment variables and other imponderables.

One example: 9th May 2006 gives Tue 09 May 2006 14:50:10 UTC

Note:
QOF_DATE_FORMAT_CUSTOM includes locale-specific format specifiers and therefore cannot support the full range of QofDate. see QofDate and locales.

Definition at line 319 of file qofdate.h.

#define QOF_DATE_FORMAT_ISO   4

Short ISO form. "%F".

9th May 2006 == 2006-05-09

Definition at line 268 of file qofdate.h.

#define QOF_DATE_FORMAT_ISO8601   6

Date and time with nanoseconds and timezone.

"%Y-%m-%d %H:%M:%S.%N %z"

12th July 2006 gives 2006-07-12 17:08:16.329768000 +0000 in UTC. Timezones can be specified and will then be converted into UTC at validation.

Definition at line 287 of file qofdate.h.

#define QOF_DATE_FORMAT_LOCALE   7

GNU locale default. "%x".

QOF_DATE_FORMAT_LOCALE and QOF_DATE_FORMAT_CUSTOM are only suitable for date / time display - storing these values in any kind of file is a recipe for disaster as the exact format can be affected by environment variables and other imponderables.

One example: 9th May 2006 gives 09/05/06

Note:
QOF_DATE_FORMAT_LOCALE includes locale-specific format specifiers and therefore cannot support the full range of QofDate. see QofDate and locales.

Definition at line 303 of file qofdate.h.

#define QOF_DATE_FORMAT_UK   2

United Kingdom default. "%d/%m/%Y".

9th May 2006 == 09/05/2006

Definition at line 258 of file qofdate.h.

#define QOF_DATE_FORMAT_US   1

Continental US default. "%m/%d/%Y".

9th May 2006 == 05/09/2006

Definition at line 253 of file qofdate.h.

#define QOF_DATE_FORMAT_UTC   5

QOF UTC format, xsd:date compatible. QOF_UTC_DATE_FORMAT "%Y-%m-%dT%H:%M:%SZ".

xsd:date is recommended for any XML data storage of dates and times.

9th May 2006 == 2006-05-09T14:49:04Z

Definition at line 277 of file qofdate.h.

#define qof_date_isleap (   year)    ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))

Nonzero if YEAR is a leap year (every 4 years, except every 100th isn't, and every 400th is).

Definition at line 222 of file qofdate.h.

#define QOF_DAYS_TO_SEC (   x)    (x * SECS_PER_DAY)

convenience macro to turn days into seconds.

Definition at line 331 of file qofdate.h.

#define QOF_HOUR_TO_SEC (   x)    (x * SECS_PER_HOUR)

convenience macro to turn hours into seconds.

Definition at line 327 of file qofdate.h.

#define QOF_MIN_TO_SEC (   x)    (x * 60)

convenience macro to turn minutes into seconds.

Definition at line 329 of file qofdate.h.

#define QOF_MOD_DATE   "qof-dates"

QofLogModule name for QofDate

Definition at line 98 of file qofdate.h.

#define QOF_UTC_DATE_FORMAT   "%Y-%m-%dT%H:%M:%SZ"

UTC date format string.

Timezone independent, date and time inclusive, as used in the QSF backend. The T and Z characters are from xsd:dateTime format in coordinated universal time, UTC. You can reproduce the string from the GNU/Linux command line using the date utility:

$ date -u +%Y-%m-%dT%H:M:SZ 
2004-12-12T23:39:11Z
 

The datestring must be timezone independent and include all specified fields. Remember to use gmtime() NOT localtime()!

Definition at line 244 of file qofdate.h.

#define SECS_PER_DAY   86400

number of seconds in one whole day.

Definition at line 94 of file qofdate.h.

#define SECS_PER_HOUR   3600

number of seconds in one whole hour.

Definition at line 96 of file qofdate.h.


Typedef Documentation

typedef struct QofDate_s QofDate

Full range replacement for struct tm.

Based on struct tm but using signed integers. The year value uses a signed 64bit value to prevent overflows. (A glong is insufficient by two orders of magnitude.) To retain precision, a QofDate includes a nanoseconds value that can be used with a QofTime and a 64bit value for seconds.

Note:
All QofDate values can be negative. The normalising cascade handles rollovers. e.g. If a QofDate qd_min value is 5 initially, setting qd_sec to 68 causes qd_sec to actually hold the value 8 and qd_min to hold the value 6. Alternatively, setting qd_sec to -64 with qd_min set to 5 causes qd_sec to hold the value 56 and qd_min to hold the value 3.
Todo:
check - years work like this, days don't!! Only qd_year retains a negative value once set. Adding one year to a negative QofDate causes the QofDate to be set to one year further into the past. This follows the same pattern as typical BC dates: the 1st of May 501BC is further into the past than the 5th of May 500BC.

Why is this a date? Because it represents a date, broken down into the component variables. A QofTime always (and only) relates to seconds, a QofDate always relates to how that number of seconds can be represented as a sequence of days, months, years etc.

Note:
Although values can be set directly, qof_date_valid should be called before attempting to manipulate a QofDate.
Todo:
Reorganise the qof_time_* functions to reflect this statement. qof_time_set_day_end should be qof_date_set_day_end and the various qof_date_time functions need to be reviewed.
typedef gint QofDateFormat

Index value of the selected QofDateFormat in the DateFormatTable

Definition at line 335 of file qofdate.h.


Function Documentation

gboolean qof_date_adddays ( QofDate qd,
gint  days 
)

Add a number of days to a QofDate and normalise.

Parameters:
qdA valid QofDate.
daysNumber of days to add - use negative value to subtract.
Returns:
FALSE on error, otherwise TRUE.

Definition at line 991 of file qofdate.c.

{
    g_return_val_if_fail (qd, FALSE);
    g_return_val_if_fail (qof_date_valid (qd), FALSE);
    qd->qd_mday += days;
    return qof_date_valid (qd);
}
gboolean qof_date_addmonths ( QofDate qd,
gint  months,
gboolean  track_last_day 
)

Add (or subtract) months from a QofDate

Optionally tracks the last day of the month so that if the original QofDate is the last day of the month in the specified year, the updated QofDate will also be the last day of the updated month in the updated year.

Parameters:
qdA QofDate which will be normalised before calculations begin.
monthsNumber of months to add (or subtract if months is negative).
track_last_dayWhether to track the last day.
Returns:
FALSE on error, otherwise TRUE.

Definition at line 1000 of file qofdate.c.

{
    g_return_val_if_fail (qd, FALSE);
    g_return_val_if_fail (qof_date_valid (qd), FALSE);
    qd->qd_mon += months % 12;
    qd->qd_year += months / 12;
    g_return_val_if_fail (qof_date_valid (qd), FALSE);
    if (track_last_day && qof_date_is_last_mday (qd))
    {
        qd->qd_mday = qof_date_get_mday (qd->qd_mon,
            qd->qd_year);
    }
    return TRUE;
}
gint qof_date_compare ( const QofDate d1,
const QofDate d2 
)

Compare two QofDates

Definition at line 662 of file qofdate.c.

{
    if ((!d1) && (!d2))
        return 0;
    if (d1 == d2)
        return 0;
    if (!d1)
        return -1;
    if (!d2)
        return 1;
    if (d1->qd_year < d2->qd_year)
        return -1;
    if (d1->qd_year > d2->qd_year)
        return 1;
    if (d1->qd_mon < d2->qd_mon)
        return -1;
    if (d1->qd_mon > d2->qd_mon)
        return 1;
    if (d1->qd_mday < d2->qd_mday)
        return -1;
    if (d1->qd_mday > d2->qd_mday)
        return 1;
    if (d1->qd_hour < d2->qd_hour)
        return -1;
    if (d1->qd_hour > d2->qd_hour)
        return 1;
    if (d1->qd_min < d2->qd_min)
        return -1;
    if (d1->qd_min > d2->qd_min)
        return 1;
    if (d1->qd_sec < d2->qd_sec)
        return -1;
    if (d1->qd_sec > d2->qd_sec)
        return 1;
    if (d1->qd_nanosecs < d2->qd_nanosecs)
        return -1;
    if (d1->qd_nanosecs > d2->qd_nanosecs)
        return 1;
    return 0;
}
gboolean qof_date_equal ( const QofDate d1,
const QofDate d2 
)

Check two QofDates for equality

Definition at line 654 of file qofdate.c.

{
    if (0 == qof_date_compare (d1, d2))
        return TRUE;
    return FALSE;
}
gboolean qof_date_format_add ( const gchar *  str,
QofDateFormat identifier 
)

Add a specific strftime compatible string as a new QofDateFormat.

Unlike GDate, QofDate allows time-related formats.

Parameters:
strA pre-formatted string, suitable to be passed directly to strftime.
identifierinteger pointer. Will be set to the positive value to be used to identify this date format later.
Returns:
TRUE on success, otherwise FALSE
Todo:
Move to QofDate and qofgmtime_r

Definition at line 202 of file qofdate.c.

{
    struct tm check;
    gint len;
    time_t now;
    gchar test[MAX_DATE_BUFFER];

    g_return_val_if_fail (QofDateInit, FALSE);
    g_return_val_if_fail (str, FALSE);
    g_return_val_if_fail (strlen (str) != 0, FALSE);
    /* prevent really long strings being passed */
    ENTER (" str=%s", str);
    if (strlen (str) > MAX_DATE_LENGTH)
    {
        LEAVE (" '%s' is too long! Max=%d str_len=%d",
            str, MAX_DATE_LENGTH, (gint) strlen (str));
        return FALSE;
    }
    /* test the incoming string using the current time. */
    now = time (NULL);
    test[0] = '\1';
    check = *gmtime_r (&now, &check);
    /* need to allow time related formats - 
    don't use g_date_strftime here. */
    len = strftime (test, (MAX_DATE_BUFFER - 1), str, &check);
    if (len == 0 && test[0] != '\0')
    {
        LEAVE (" strftime could not understand '%s'", str);
        return FALSE;
    }
    len = strlen (test);
    if (len > MAX_DATE_LENGTH)
    {
        LEAVE (" %s creates a string '%s' that is too long!"
            " Max=%d str_len=%d", str, test, MAX_DATE_LENGTH, len);
        return FALSE;
    }
    *identifier = g_hash_table_size (DateFormatTable) + 1;
    {
        QofDateEntry *d = g_new0 (QofDateEntry, 1);
        d->format = str;
        d->name = str;
        d->separator = locale_separator;
        d->df = *identifier;
        g_hash_table_insert (DateFormatTable, GINT_TO_POINTER (d->df), d);
    }
    LEAVE (" successful");
    return TRUE;
}
QofDateFormat qof_date_format_from_name ( const gchar *  name)

Returns the default date format for a known shorthand name.

If the selected QofDateFormat is one of the defaults, the shorthand "name" is returned. If format is not a default, returns negative one.

Parameters:
nameShorthand "name" of this format.
Returns:
the QofDateFormat on success, negative one on failure.

Definition at line 385 of file qofdate.c.

{
    struct iter i;

    if (!name)
        return -1;
    if (0 == safe_strcmp (name, "us"))
        return QOF_DATE_FORMAT_US;
    if (0 == safe_strcmp (name, "uk"))
        return QOF_DATE_FORMAT_UK;
    if (0 == safe_strcmp (name, "ce"))
        return QOF_DATE_FORMAT_CE;
    if (0 == safe_strcmp (name, "utc"))
        return QOF_DATE_FORMAT_UTC;
    if (0 == safe_strcmp (name, "iso"))
        return QOF_DATE_FORMAT_ISO;
    if (0 == safe_strcmp (name, "locale"))
        return QOF_DATE_FORMAT_LOCALE;
    if (0 == safe_strcmp (name, "custom"))
        return QOF_DATE_FORMAT_CUSTOM;
    i.name = name;
    i.df = -1;
    g_hash_table_foreach (DateFormatTable, lookup_name, &i);
    return i.df;
}
gchar qof_date_format_get_date_separator ( QofDateFormat  df)

Return the field separator for the current date format.

Note:
The separator only relates to the date portion of any date format string, i.e. the separator used between day, month and year. Separators used between time fields like hour, minute, second in any date format are not available.
Returns:
date single non-digit character to separate fields within the date section of a date format or a null on error.

Definition at line 325 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, locale_separator);
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (df));
    if (!d)
    {
        PERR (" unknown format: '%d'", df);
        return locale_separator;
    }
    return d->separator;
}
const gchar* qof_date_format_get_format ( QofDateFormat  df)

Retrieve the strftime format string for a registered date format.

Parameters:
dfThe QofDateFormat identifier for the registered date format.
Returns:
The format string for this date format or NULL on error.

Definition at line 310 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, NULL);
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (df));
    if (!d)
    {
        PERR (" unknown format: '%d'", df);
        return NULL;
    }
    return d->format;
}
gboolean qof_date_format_set_current ( QofDateFormat  df)

Selects one registered date format as the current default.

Parameters:
dfQofDateFormat identifier indicating preferred format.
Returns:
TRUE on success, else FALSE.

Definition at line 294 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, FALSE);
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (df));
    if (!d)
    {
        PERR (" unknown format: '%d'", df);
        return FALSE;
    }
    dateFormat = d->df;
    return TRUE;
}
gboolean qof_date_format_set_date_separator ( const gchar  sep,
QofDateFormat  df 
)

Set a locale-specific separator.

Sets the date separator for a date format added using qof_date_format_add.

Returns:
FALSE if date format is not one of the QOF defaults or if the character is a digit, TRUE on success.

Definition at line 340 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, FALSE);
    if (df < DATE_FORMAT_LAST)
    {
        DEBUG (" Prevented attempt to override a default format");
        return FALSE;
    }
    if (g_ascii_isdigit (sep))
        return FALSE;
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (df));
    if (!d)
    {
        PERR (" unknown format: '%d'", df);
        return FALSE;
    }
    d->separator = sep;
    g_hash_table_insert (DateFormatTable, GINT_TO_POINTER (df), d);
    return TRUE;
}
gboolean qof_date_format_set_name ( const gchar *  name,
QofDateFormat  format 
)

Set a shorthand name for a custom date format.

Used alongside qof_date_format_add to allow any date format to have a shorthand name.

Parameters:
nameShorthand name for a date format added with qof_date_format_add. The string becomes the property of QofDate and should not be freed.
formatidentifier used previously with qof_date_format_add
Returns:
TRUE if the shorthand name can be set, FALSE on error or if the chosen QofDateFormat is one of the defaults.

Definition at line 269 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, FALSE);
    if (format <= DATE_FORMAT_LAST)
        return FALSE;
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (format));
    if (!d)
    {
        PERR (" unknown format: '%d'", format);
        return FALSE;
    }
    d->name = name;
    g_hash_table_insert (DateFormatTable, GINT_TO_POINTER (format), d);
    return TRUE;
}
const gchar* qof_date_format_to_name ( QofDateFormat  format)

Retrieve the shorthand name for the selected date format.

If the selected QofDateFormat is one of the defaults, a shorthand "name" is used. If it is a string added using qof_date_add_format, the string itself is returned.

Parameters:
formatThe QofDateFormat to lookup.
Returns:
FALSE on success and TRUE on failure.

Definition at line 254 of file qofdate.c.

{
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, NULL);
    d = g_hash_table_lookup (DateFormatTable, GINT_TO_POINTER (format));
    if (!d)
    {
        PERR (" unknown format: '%d'", format);
        return NULL;
    }
    return d->name;
}
void qof_date_free ( QofDate date)

free a QofDate

Definition at line 633 of file qofdate.c.

{
    g_return_if_fail (date);
    g_free (date);
    date = NULL;
}
QofDate* qof_date_from_gdate ( const GDate *  gd)

Create a QofDate from a GDate.

A GDate is always within the range of a QofDate.

Parameters:
gdA valid GDate.
Returns:
NULL on error, otherwise a newly allocated, valid, QofDate.

Definition at line 775 of file qofdate.c.

{
    QofDate * qd;

    g_return_val_if_fail (g_date_valid (date), NULL);
    qd = qof_date_new ();
    qd->qd_year = g_date_get_year (date);
    qd->qd_mon  = g_date_get_month (date);
    qd->qd_mday = g_date_get_day (date);
    qd = date_normalise (qd);
    return qd;
}
QofDate* qof_date_from_qtime ( const QofTime qt)

Return a QofDate in UTC from a QofTime.

Definition at line 875 of file qofdate.c.

{
    QofDate *qd;
    gint leap_extra_secs;

    /* may not want to create a new time or date - it
    complicates memory management. */
    g_return_val_if_fail (qt, NULL);
    g_return_val_if_fail (qof_time_is_valid (qt), NULL);
    qd = qof_date_new ();
    leap_extra_secs = 0;
    setenv ("TZ", "GMT", 1);
    tzset();
    leap_extra_secs = extract_interval (qt);
    qof_date_offset (qt, leap_extra_secs, qd);
    qd->qd_nanosecs = qof_time_get_nanosecs (qt);
    qd->qd_is_dst = 0;
    qd->qd_zone = "GMT";
    qd->qd_gmt_off = 0L;
    if (!qof_date_valid(qd))
        return NULL;
    return qd;
}
QofDate* qof_date_from_struct_tm ( const struct tm *  stm)

Convert a struct tm to a QofDate.

Parameters:
stmA pointer to a valid struct tm.
Returns:
Newly allocated QofDate or NULL if tm is NULL.

Definition at line 704 of file qofdate.c.

{
    QofDate *d;

    g_return_val_if_fail (stm, NULL);
    d = g_new0 (QofDate, 1);
    d->qd_sec  = stm->tm_sec;
    d->qd_min  = stm->tm_min;
    d->qd_hour = stm->tm_hour;
    d->qd_mday = stm->tm_mday;
    d->qd_mon  = stm->tm_mon + 1;
    d->qd_year = stm->tm_year + 1900;
    d->qd_wday = stm->tm_wday;
    d->qd_yday = stm->tm_yday;
    d->qd_is_dst = stm->tm_isdst;
    d->qd_gmt_off = stm->tm_gmtoff;
    d->qd_zone = stm->tm_zone;
    d->qd_valid = TRUE;
    d = date_normalise(d);
    return d;
}
QofDate* qof_date_get_current ( void  )

create a new QofDate for the current date and time.

Definition at line 607 of file qofdate.c.

{
    QofTime *qt;
    QofDate *qd;

    qt = qof_time_get_current ();
    qd = qof_date_from_qtime (qt);
    qof_time_free (qt);
    return qd;
}
guint8 qof_date_get_mday ( gint  month,
gint64  year 
)

full range version of g_date_get_days_in_month

Parameters:
monthAny valid QofDate qd_mon, 1 to 12.
yearAny valid QofDate qd_year.
Returns:
0 on error, otherwise the number of days in the specified month, taking leap years into account.

Definition at line 183 of file qofdate.c.

{
    g_return_val_if_fail (month !=  0, 0);
    g_return_val_if_fail (month <= 12, 0);
    g_return_val_if_fail (month >=  1, 0);
    g_return_val_if_fail (year  !=  0, 0);
    return days_in_months[qof_date_isleap (year)][month];
}
guint16 qof_date_get_yday ( gint  mday,
gint  month,
gint64  year 
)

full range version of g_date_get_day_of_year

Parameters:
mdayAny valid QofDate qd_mday, 1 to 31.
monthAny valid QofDate qd_mon, 1 to 12.
yearAny valid QofDate qd_year.
Returns:
0 if error, otherwise the day of the year, where Jan 1 is 1, the first day of the year.

Definition at line 167 of file qofdate.c.

{
    guint8 leap;

    g_return_val_if_fail (mday  != 0, 0);
    g_return_val_if_fail (month != 0, 0);
    g_return_val_if_fail (month <= 12, 0);
    g_return_val_if_fail (month >= 1, 0);
    g_return_val_if_fail (year  != 0, 0);
    leap = qof_date_isleap (year);
    g_return_val_if_fail (mday <= 
        qof_date_get_mday (month, year), 0);
    return days_in_year[leap][month] + mday;
}
gboolean qof_date_is_last_mday ( const QofDate qd)

Checks if QofDate the last day of the month.

Parameters:
qdA valid QofDate.
Returns:
TRUE if qd_mday is the last day of qd_mon in qd_year, otherwise (or on error), FALSE.

Definition at line 193 of file qofdate.c.

{
    g_return_val_if_fail (qd, FALSE);
    g_return_val_if_fail (qd->qd_valid, FALSE);
    return (qd->qd_mday == 
        qof_date_get_mday (qd->qd_mon, qd->qd_year));
}
QofDate* qof_date_new ( void  )

create a new, empty, QofDate

Definition at line 598 of file qofdate.c.

{
    QofDate *d;

    d = g_new0 (QofDate, 1);
    return d;
}
QofDate* qof_date_new_dmy ( gint  day,
gint  month,
gint64  year 
)

create a new QofDate from basic calendar data.

Definition at line 619 of file qofdate.c.

{
    QofDate *qd;

    qd = g_new0 (QofDate, 1);
    qd->qd_mday = day;
    qd->qd_mon  = month;
    qd->qd_year = year;
    if(!qof_date_valid (qd))
        return NULL;
    return qd;
}
QofDate* qof_date_parse ( const gchar *  str,
QofDateFormat  df 
)

Convert a timestamp to a QofTime.

Safe for all dates within the range of QofDate.

Parameters:
stra timestamp created with one of the registered QofDateFormat formats.
dfThe registered QofDateFormat that produced the string.
Returns:
a newly allocated, valid, QofDate or NULL on error.

Definition at line 549 of file qofdate.c.

{
    const gchar *format;
    QofDateError error;
    QofDate *date;
    gchar *check;

    check = NULL;
    error = ERR_NO_ERROR;
    date = qof_date_new ();
    format = qof_date_format_get_format (df);
    check = strptime_internal (str, format, date, &error);
    if (error != ERR_NO_ERROR)
    {
        qof_date_free (date);
        return NULL;
    }

    date = date_normalise (date);
    return date;
}
gchar* qof_date_print ( const QofDate date,
QofDateFormat  df 
)

Convert a QofDate to a timestamp according to the specified date format.

Unlike qof_time_stamp_now, any supported QofDate can be converted in any registered QofDateFormat.

Parameters:
dateA valid QofDate.
dfa registered QofDateFormat to use to create the string.
Returns:
NULL on error, otherwise a string which should be freed when no longer needed.

Definition at line 572 of file qofdate.c.

{
    size_t result;
    gchar temp[MAX_DATE_BUFFER];
    QofDateEntry *d;

    g_return_val_if_fail (QofDateInit, NULL);
    g_return_val_if_fail (date, NULL);
    g_return_val_if_fail (date->qd_valid, NULL);
    d = g_hash_table_lookup (DateFormatTable, 
        GINT_TO_POINTER (df));
    g_return_val_if_fail (d, NULL);
    temp[0] = '\1';
    result = strftime_case (FALSE, temp, MAX_DATE_BUFFER, 
        d->format, date, 1, date->qd_nanosecs);
    if (result == 0 && temp[0] != '\0')
    {
        PERR (" qof extended strftime failed");
        return NULL;
    }
    return g_strndup(temp, result);
}
QofTime* qof_date_time_difference ( const QofDate date1,
const QofDate date2 
)

Calculate the QofTime between two QofDates

Definition at line 950 of file qofdate.c.

{
    gint64 days;
    QofTime *secs;

    secs = qof_time_new ();
    days = days_between (date1->qd_year, date2->qd_year);
    qof_time_add_secs(secs, QOF_DAYS_TO_SEC(days));
    if (days >= 0)
    {
        /* positive value, add date2 secs, subtract date1 */
        qof_time_add_secs(secs, -1 *
                (QOF_HOUR_TO_SEC(date1->qd_hour) -
                QOF_MIN_TO_SEC(date1->qd_min) -
                (date1->qd_sec)));
        qof_time_add_secs(secs,
                QOF_HOUR_TO_SEC(date2->qd_hour) +
                QOF_MIN_TO_SEC(date2->qd_min) +
                (date2->qd_sec));
        qof_time_set_nanosecs(secs, 
            (date1->qd_nanosecs - date2->qd_nanosecs));
    }
    if (days < 0)
    {
        /* negative value*/
        qof_time_add_secs (secs, 
                QOF_HOUR_TO_SEC(date1->qd_hour) -
                QOF_MIN_TO_SEC(date1->qd_min) -
                (date1->qd_sec));
        qof_time_add_secs (secs, -1 * 
                (QOF_HOUR_TO_SEC(date2->qd_hour) +
                QOF_MIN_TO_SEC(date2->qd_min) +
                (date2->qd_sec)));
        qof_time_set_nanosecs(secs, 
            (date2->qd_nanosecs - date1->qd_nanosecs));
    }
    return secs;
}
gboolean qof_date_to_gdate ( const QofDate qd,
GDate *  gd 
)

Convert a QofDate to a GDate.

Parameters:
qda valid QofDate
gda new GDate to store the converted value.
Returns:
FALSE on error, if the QofDate is out of range of a GDate or if QofDate is not valid, otherwise TRUE.

Definition at line 755 of file qofdate.c.

{
    g_return_val_if_fail (qd, FALSE);
    g_return_val_if_fail (gd, FALSE);
    g_return_val_if_fail (qd->qd_valid, FALSE);
    if (qd->qd_year >= G_MAXUINT16)
    {
        PERR (" QofDate out of range of GDate");
        return FALSE;
    }
    if (!g_date_valid_dmy (qd->qd_mday, qd->qd_mon, qd->qd_year))
    {
        PERR (" GDate failed to allow day, month and/or year");
        return FALSE;
    }
    g_date_set_dmy (gd, qd->qd_mday, qd->qd_mon, qd->qd_year);
    return TRUE;
}
QofTime* qof_date_to_qtime ( const QofDate qd)

Return a valid QofTime from a valid QofDate.

Definition at line 917 of file qofdate.c.

{
    QofTime *qt;
    QofTimeSecs c;

    g_return_val_if_fail (qd, NULL);
    g_return_val_if_fail (qd->qd_valid, NULL);
    c = 0;
    qt = NULL;
    if (qd->qd_year < 1970)
    {
        c = qd->qd_sec;
        c += QOF_MIN_TO_SEC(qd->qd_min);
        c += QOF_HOUR_TO_SEC(qd->qd_hour);
        c += QOF_DAYS_TO_SEC(qd->qd_yday);
        c -= QOF_DAYS_TO_SEC(days_between (1970, qd->qd_year));
        c -= qd->qd_gmt_off;
        qt = qof_time_set (c, qd->qd_nanosecs);
    }
    if (qd->qd_year >= 1970)
    {
        c = qd->qd_sec;
        c += QOF_MIN_TO_SEC(qd->qd_min);
        c += QOF_HOUR_TO_SEC(qd->qd_hour);
        c += QOF_DAYS_TO_SEC(qd->qd_yday);
        c += QOF_DAYS_TO_SEC(days_between (1970, qd->qd_year));
        c -= qd->qd_gmt_off;
        qt = qof_time_set (c, qd->qd_nanosecs);
    }
    return qt;
}
gboolean qof_date_to_struct_tm ( const QofDate qt,
struct tm *  stm,
glong *  nanosecs 
)

Convert a QofDate to a struct tm.

Warning:
Check the return value - a QofDate has a larger range than a struct tm. The struct tm will be unchanged if a conversion would have been out of range.
Parameters:
qtA valid QofDate.
stmPointer to a struct tm to store the result.
nanosecsPointer to a glong to store the nanoseconds.
Returns:
FALSE on error or if the QofDate is invalid or out of the range of a struct tm, otherwise TRUE.

Definition at line 727 of file qofdate.c.

{
    g_return_val_if_fail (qd, FALSE);
    g_return_val_if_fail (stm, FALSE);
    g_return_val_if_fail (qd->qd_valid, FALSE);
    if ((qd->qd_year > G_MAXINT) || (qd->qd_year < 1900))
    {
        PERR (" date too large for struct tm");
        return FALSE;
    }
    stm->tm_sec  = qd->qd_sec;
    stm->tm_min  = qd->qd_min;
    stm->tm_hour = qd->qd_hour;
    stm->tm_mday = qd->qd_mday;
    stm->tm_mon  = qd->qd_mon - 1;
    stm->tm_year = qd->qd_year - 1900;
    stm->tm_wday = qd->qd_wday;
    stm->tm_yday = qd->qd_yday;
    stm->tm_isdst = qd->qd_is_dst;
    stm->tm_gmtoff = qd->qd_gmt_off;
    stm->tm_zone = qd->qd_zone;
    if (nanosecs != NULL)
        *nanosecs = qd->qd_nanosecs;
    return TRUE;
}
gboolean qof_date_valid ( QofDate date)

Validate a QofDate.

If the QofDate is already valid, just returns TRUE. If the QofDate is not valid but can be normalised, the QofDate is normalised and the function returns TRUE. If the QofDate cannot be normalised, returns FALSE.

Year Zero does not exist in the Christian Era, the Gregorian calendar or the Julian calendar. A year zero does exist in ISO 8601:2004 and in the astronomical year numbering with a defined year zero equal to 1 BC, as well as in some Buddhist and Hindu lunar calendars.

In QofDate, 1BC is immediately followed by 1AD and months are numbered from 1 to 12, not from zero.

Normalising a QofDate tries to use sensible defaults:

  • if qd_mon == 0, validating sets qd_mon to 1 (January)
  • if qd_year == 0, validating sets qd_year to -1 (1BC).
  • if qd_mday == 0, validating sets qd_mday to 1.

Definition at line 641 of file qofdate.c.

{
    g_return_val_if_fail (date, FALSE);
    date = date_normalise (date);
    if (date->qd_valid == FALSE)
    {
        PERR (" unknown QofDate error");
        return FALSE;
    }
    return TRUE;
}