DateReturns number of days for the given month and year for gregorian calendar. Takes into account leap years.
time_elapsed start stop Compute the time elapsed between start and stop. If stop is prior to start, resulting dmy's field are negative (but correct). Resulting prec can be:
Sure for exact durationBefore for "less than" durationAfter for "more than" durationMaybe for other cases Used to compare only gregorian calendar's dates.Same as time_elapsed, but will return None if computation is not possible (e.g. time_elapsed_opt /1839 /1859).
dmy_of_dmy2 dmy2 Convert a dmy2 to dmy using Sure as precision.
Not_comparable is raised by compare_dmy and compare_date when strict mode is used and precision of dates are incompatibles to have a reliable result (e.g. is compare_dmy 2019 07/2019) or when one of the date in compare_date is Dtext.
compare_dmy ?strict d1 d2 Return a negative integer if d1 is prior to d2, 0 if d1 is equal to d2, and a positive integer if d2 is prior to d1. strict parameter enable or disable strict mode, and is false by default (see Not_comparable)
compare_dmy_opt ?strict d1 d2 Same as compare_dmy, but do not raise an exception
compare_date d1 d2 If both d1 and d2 are Dgreg date, uses compare_dmy to compare them. Dtext dates are always considered prior to any Dgreg date, and equal to any other Dtext date. strict parameter enable or disable strict mode, and is false by default (see Not_comparable)
val cdate_None : Def.cdateAbsent compressed date
cdate_to_dmy_opt d is Some dmy iff d resolve to Dgreg (dmy,_)