glib.date
Module for [Date] struct
Types 1
[glib.date.Date] is a struct for calendrical calculations.
The [glib.date.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.Date.setParse] only parses up to the year 8000 or so - just count on "a few thousand"). [glib.date.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.Date] does not store time information; it represents a day.
The [glib.date.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 #GDate the fixed day is January 1, 1 AD. ("Julian" dates in the #GDate 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.Date] is simple to use. First you need a "blank" date; you can get a dynamically allocated date from [glib.date.Date.new_], or you can declare an automatic variable or array and initialize it by calling [glib.date.Date.clear]. A cleared date is safe; it's safe to call [glib.date.Date.setDmy] 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.Date.valid] predicate. [glib.date.Date.valid] is also used to check for errors with [glib.date.Date.setParse] and other functions that can fail. Dates can be invalidated by calling [glib.date.Date.clear] again.
It is very important to use the API to access the [glib.date.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.date_time.DateTime] which represents a precise time.
uint julianDaysthe Julian representation of the dateuint julianthis bit is set if @julian_days is validuint dmythis is set if @day, @month and @year are validuint daythe day of the day-month-year representation of the date, as a number between 1 and 31uint monththe month of the day-month-year representation of the date, as a number between 1 and 12uint yearthe year of the day-month-year representation of the datevoid * boxCopy()string strftime(string format)Generates a printed representation of the date, in a [locale][setlocale]-specific way. Works just like the platform's C library strftime() function, but only accepts date-related formats; time-rela...void addDays(uint nDays)Increments a date some number of days. To move forward by weeks, add weeks*7 days. The date must be valid.void addMonths(uint nMonths)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 i...void addYears(uint nYears)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.void clamp(glib.date.Date minDate, glib.date.Date maxDate)If date is prior to mindate, sets date equal to mindate. If date falls after maxdate, sets date equal to maxdate. Otherwise, date is unchanged. Either of mindate and maxdate may be null. All non-nu...void clear(uint nDates)Initializes one or more #GDate 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....int compare(glib.date.Date rhs)qsort()-style comparison function for dates. Both dates must be valid.glib.date.Date copy()Copies a GDate to a newly-allocated GDate. If the input was invalid (as determined by [glib.date.Date.valid]), the invalid state will be copied as is into the new object. Returns: a newly-allocated...int daysBetween(glib.date.Date date2)Computes the number of days between two dates. If date2 is prior to date1, the returned value is negative. Both dates must be valid.glib.types.DateDay getDay()Returns the day of the month. The date must be valid. Returns: day of the monthuint getDayOfYear()Returns the day of the year, where Jan 1 is the first day of the year. The date must be valid. Returns: day of the yearuint getIso8601WeekOfYear()Returns the week of the year, where weeks are interpreted according to ISO 8601. Returns: ISO 8601 week number of the year.uint getJulian()Returns the Julian day or "serial number" of the #GDate. 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 da...uint getMondayWeekOfYear()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. Returns: week of the yearglib.types.DateMonth getMonth()Returns the month of the year. The date must be valid. Returns: month of the year as a #GDateMonthuint getSundayWeekOfYear()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. Return...glib.types.DateWeekday getWeekday()Returns the day of the week for a #GDate. The date must be valid. Returns: day of the week as a #GDateWeekday.glib.types.DateYear getYear()Returns the year of a #GDate. The date must be valid. Returns: year in which the date fallsbool isFirstOfMonth()Returns true if the date is on the first of a month. The date must be valid. Returns: true if the date is the first of the monthbool isLastOfMonth()Returns true if the date is the last day of the month. The date must be valid. Returns: true if the date is the last day of the monthvoid order(glib.date.Date date2)Checks if date1 is less than or equal to date2, and swap the values if this is not the case.void setDay(glib.types.DateDay day)Sets the day of the month for a #GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.void setDmy(glib.types.DateDay day, glib.types.DateMonth month, glib.types.DateYear y)Sets the value of a #GDate from a day, month, and year. The day-month-year triplet must be valid; if you aren't sure it is, call [glib.date.Date.validDmy] to check before you set it.void setJulian(uint julianDate)Sets the value of a #GDate from a Julian day number.void setMonth(glib.types.DateMonth month)Sets the month of the year for a #GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.void setParse(string str)Parses a user-inputted string str, and try to figure out what date it represents, taking the [current locale][setlocale] into account. If the string is successfully parsed, the date will be valid a...void setTime(glib.types.Time time)Sets the value of a date from a #GTime value. The time to date conversion is done using the user's current timezone.void setTimeT(long timet)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.void setTimeVal(glib.time_val.TimeVal timeval)Sets the value of a date from a #GTimeVal value. Note that the tv_usec member is ignored, because #GDate can't make use of the additional precision.void setYear(glib.types.DateYear year)Sets the year for a #GDate. If the resulting day-month-year triplet is invalid, the date will be invalid.void subtractDays(uint nDays)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.void subtractMonths(uint nMonths)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.void subtractYears(uint nYears)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...void toStructTm(void * tm)Fills in the date-related bits of a struct tm using the date value. Initializes the non-date parts with something safe but meaningless.bool valid()Returns true if the #GDate represents an existing day. The date must not contain garbage; it should have been initialized with [glib.date.Date.clear] if it wasn't allocated by one of the [glib.date...ubyte getDaysInMonth(glib.types.DateMonth month, glib.types.DateYear year)Returns the number of days in a month, taking leap years into account.ubyte getMondayWeeksInYear(glib.types.DateYear year)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...ubyte getSundayWeeksInYear(glib.types.DateYear year)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...bool isLeapYear(glib.types.DateYear year)Returns true if the year is a leap year.bool validDay(glib.types.DateDay day)Returns true if the day of the month is valid (a day is valid if it's between 1 and 31 inclusive).bool validDmy(glib.types.DateDay day, glib.types.DateMonth month, glib.types.DateYear year)Returns true if the day-month-year triplet forms a valid, existing day in the range of days #GDate understands (Year 1 or later, no more than a few thousand years in the future).bool validJulian(uint julianDate)Returns true if the Julian day is valid. Anything greater than zero is basically a valid Julian, though there is a 32-bit limit.bool validMonth(glib.types.DateMonth month)Returns true if the month value is valid. The 12 #GDateMonth enumeration values are the only valid months.bool validWeekday(glib.types.DateWeekday weekday)Returns true if the weekday is valid. The seven #GDateWeekday enumeration values are the only valid weekdays.bool validYear(glib.types.DateYear year)Returns true if the year is valid. Any year greater than 0 is valid, though there is a 16-bit limit to what #GDate will understand.