Static$gtypeIncrements a date some number of days. To move forward by weeks, add weeks*7 days. The date must be valid.
number of days to move the date forward
Increments a date by some number of months. If the day of the month is greater than 28, this routine may change the day of the month (because the destination month may not have the current day in it). The date must be valid.
number of months to move forward
Increments a date by some number of years. If the date is February 29, and the destination year is not a leap year, the date will be changed to February 28. The date must be valid.
number of years to move forward
If date is prior to min_date, sets date equal to min_date.
If date falls after max_date, sets date equal to max_date.
Otherwise, date is unchanged.
Either of min_date and max_date may be null.
All non-null dates must be valid.
Initializes one or more GLib.Date structs to a safe but invalid
state. The cleared dates will not represent an existing date, but will
not contain garbage. Useful to init a date declared on the stack.
Validity can be tested with g_date_valid().
number of dates to clear
Frees a GLib.Date returned from g_date_new().
Returns the day of the month. The date must be valid.
day of the month
Returns the day of the year, where Jan 1 is the first day of the year. The date must be valid.
day of the year
Returns the week of the year, where weeks are interpreted according to ISO 8601.
ISO 8601 week number of the year.
Returns the Julian day or "serial number" of the GLib.Date. The Julian day is simply the number of days since January 1, Year 1; i.e., January 1, Year 1 is Julian day 1; January 2, Year 1 is Julian day 2, etc. The date must be valid.
Julian day
Returns the week of the year, where weeks are understood to start on Monday. If the date is before the first Monday of the year, return 0. The date must be valid.
week of the year
Returns the month of the year. The date must be valid.
month of the year as a GLib.DateMonth
Returns the week of the year during which this date falls, if weeks are understood to begin on Sunday. The date must be valid. Can return 0 if the day is before the first Sunday of the year.
week number
Calculates the week of the year during which this date falls.
The result depends on which day is considered the first day of the week,
which varies by locale. Both date and first_day_of_week must be valid.
If date is before the start of the first week of the year (for example,
before the first Monday in January if first_day_of_week is
GLib.DateWeekday.MONDAY) then zero will be returned.
the day which is considered the first day of the week (for example, this would be GLib.DateWeekday.SUNDAY in US locales, GLib.DateWeekday.MONDAY in British locales, and GLib.DateWeekday.SATURDAY in Egyptian locales
week number (starting from 1), or 0 if date is before the start of the first week of the year
Returns the day of the week for a GLib.Date. The date must be valid.
day of the week as a GLib.DateWeekday.
Returns true if the date is on the first of a month.
The date must be valid.
true if the date is the first of the month
Returns true if the date is the last day of the month.
The date must be valid.
true if the date is the last day of the month
Sets the day of the month for a GLib.Date. If the resulting day-month-year triplet is invalid, the date will be invalid.
day to set
Sets the value of a GLib.Date from a Julian day number.
Julian day number (days since January 1, Year 1)
Parses a user-inputted string str, and try to figure out what date it
represents, taking the current locale
into account. If the string is successfully parsed, the date will be
valid after the call. Otherwise, it will be invalid. You should check
using g_date_valid() to see whether the parsing succeeded.
This function is not appropriate for file formats and the like; it isn't very precise, and its exact behavior varies with the locale. It's intended to be a heuristic routine that guesses what the user means by a given string (and it does work pretty well in that capacity).
string to parse
Sets the value of a date to the date corresponding to a time specified as a time_t. The time to date conversion is done using the user's current timezone.
To set the value of a date to the current day, you could write:
time_t now = time (NULL);
if (now == (time_t) -1)
// handle the error
g_date_set_time_t (date, now);
time_t value to set
Sets the value of a date from a GLib.TimeVal value. Note that the
tv_usec member is ignored, because GLib.Date can't make use of the
additional precision.
The time to date conversion is done using the user's current timezone.
GLib.TimeVal value to set
Sets the year for a GLib.Date. If the resulting day-month-year triplet is invalid, the date will be invalid.
year to set
Moves a date some number of days into the past. To move by weeks, just move by weeks*7 days. The date must be valid.
number of days to move
Moves a date some number of months into the past. If the current day of the month doesn't exist in the destination month, the day of the month may change. The date must be valid.
number of months to move
Moves a date some number of years into the past. If the current day doesn't exist in the destination year (i.e. it's February 29 and you move to a non-leap-year) then the day is changed to February 29. The date must be valid.
number of years to move
Fills in the date-related bits of a struct tm using the date value.
Initializes the non-date parts with something safe but meaningless.
struct tm to fill
Returns true if the GLib.Date represents an existing day. The date must not
contain garbage; it should have been initialized with g_date_clear()
if it wasn't allocated by one of the g_date_new() variants.
Whether the date is valid
Staticget_Returns the number of days in a month, taking leap years into account.
month
year
Staticget_Returns the number of weeks in the year, where weeks are taken to start on Monday. Will be 52 or 53. The date must be valid. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Mondays are in the year, i.e. there are 53 Mondays if one of the extra days happens to be a Monday.)
a year
Staticget_Returns the number of weeks in the year, where weeks are taken to start on Sunday. Will be 52 or 53. The date must be valid. (Years always have 52 7-day periods, plus 1 or 2 extra days depending on whether it's a leap year. This function is basically telling you how many Sundays are in the year, i.e. there are 53 Sundays if one of the extra days happens to be a Sunday.)
year to count weeks in
Staticget_Calculates the number of weeks in the year.
The result depends on which day is considered the first day of the week,
which varies by locale. first_day_of_week must be valid.
The result will be either 52 or 53. Years always have 52 seven-day periods,
plus one or two extra days depending on whether it’s a leap year. This
function effectively calculates how many first_day_of_week days there are in
the year.
year to count weeks in
the day which is considered the first day of the week (for example, this would be GLib.DateWeekday.SUNDAY in US locales, GLib.DateWeekday.MONDAY in British locales, and GLib.DateWeekday.SATURDAY in Egyptian locales
Staticis_Returns true if the year is a leap year.
For the purposes of this function, leap year is every year divisible by 4 unless that year is divisible by 100. If it is divisible by 100 it would be a leap year only if that year is also divisible by 400.
year to check
StaticnewStaticnew_Staticnew_StaticstrftimeGenerates a printed representation of the date, in a
locale-specific way.
Works just like the platform's C library strftime() function,
but only accepts date-related formats; time-related formats
give undefined results. Date must be valid. Unlike strftime()
(which uses the locale encoding), works on a UTF-8 format
string and stores a UTF-8 result.
This function does not provide any conversion specifiers in
addition to those implemented by the platform's C library.
For example, don't expect that using g_date_strftime() would
make the F provided by the C99 strftime() work on Windows
where the C library only complies to C89.
Staticvalid_Returns true if the day of the month is valid (a day is valid if it's
between 1 and 31 inclusive).
day to check
Staticvalid_Staticvalid_Returns true if the Julian day is valid. Anything greater than zero
is basically a valid Julian, though there is a 32-bit limit.
Julian day to check
Staticvalid_Returns true if the month value is valid. The 12 GLib.DateMonth
enumeration values are the only valid months.
month
Staticvalid_Returns true if the weekday is valid. The seven GLib.DateWeekday enumeration
values are the only valid weekdays.
weekday
Staticvalid_Returns true if the year is valid. Any year greater than 0 is valid,
though there is a 16-bit limit to what GLib.Date will understand.
year
GLib.Date is a struct for calendrical calculations.
The GLib.Date data structure represents a day between January 1, Year 1, and sometime a few thousand years in the future (right now it will go to the year 65535 or so, but GLib.Date.set_parse only parses up to the year 8000 or so - just count on "a few thousand"). GLib.Date is meant to represent everyday dates, not astronomical dates or historical dates or ISO timestamps or the like. It extrapolates the current Gregorian calendar forward and backward in time; there is no attempt to change the calendar to match time periods or locations. GLib.Date does not store time information; it represents a day.
The GLib.Date implementation has several nice features; it is only a 64-bit struct, so storing large numbers of dates is very efficient. It can keep both a Julian and day-month-year representation of the date, since some calculations are much easier with one representation or the other. A Julian representation is simply a count of days since some fixed day in the past; for GLib.Date the fixed day is January 1, 1 AD. ("Julian" dates in the GLib.Date API aren't really Julian dates in the technical sense; technically, Julian dates count from the start of the Julian period, Jan 1, 4713 BC).
GLib.Date is simple to use. First you need a "blank" date; you can get a dynamically allocated date from GLib.Date.new, or you can declare an automatic variable or array and initialize it by calling GLib.Date.clear. A cleared date is safe; it's safe to call GLib.Date.set_dmy and the other mutator functions to initialize the value of a cleared date. However, a cleared date is initially invalid, meaning that it doesn't represent a day that exists. It is undefined to call any of the date calculation routines on an invalid date. If you obtain a date from a user or other unpredictable source, you should check its validity with the GLib.Date.valid predicate. GLib.Date.valid is also used to check for errors with GLib.Date.set_parse and other functions that can fail. Dates can be invalidated by calling GLib.Date.clear again.
It is very important to use the API to access the GLib.Date struct. Often only the day-month-year or only the Julian representation is valid. Sometimes neither is valid. Use the API.
GLib also features GLib.DateTime which represents a precise time.