Module Core_kernel.Date

create_exn ~y ~m ~d creates the date specified in the arguments. Arguments are validated, and are not normalized in any way. So, days must be within the limits for the month in question, numbers cannot be negative, years must be fully specified, etc.

For details on this ISO format, see:

http://www.wikipedia.org/wiki/iso8601

YYYYMMDD

YYYYMMDD

MM/DD/YYYY

Week of the year, from 1 to 53. According to ISO 8601, weeks start on Monday, and the first week of a year is the week that contains the first Thursday of the year. Notice that this means that dates near the end of the year can have week number 1, and dates near the beginning of the year can have week number 52 or 53.

Warning: the triple (year, week number, week day) does not identify a date -- e.g. 2012-01-02 and 2012-12-31 are both Mondays of week 1. (However, if instead of the year, you use the year of the nearest Thursday, then it does work.)

Monday through Friday are business days, unless they're a holiday.

add_days t n adds n days to t and returns the resulting date.

add_months t n returns date with max days for the month if the date would be invalid. e.g. adding 1 month to Jan 30 results in Feb 28 due to Feb 30 being an invalid date, Feb 29 is returned in cases of leap year.

In particular, this means adding x months and then adding y months isn't the same as adding x + y months, and in particular adding x months and then -x months won't always get you back where you were. *

add_years t n has the same semantics as add_months for adding years to Feb 29 of a leap year, i.e., when the addition results in a date in a non-leap year, the result will be Feb 28 of that year.

diff t1 t2 returns date t1 minus date t2 in days.

diff_weekdays t1 t2 returns the number of weekdays in the half-open interval [t2,t1) if t1 >= t2, and - diff_weekdays t2 t1 otherwise.

diff_weekend_days t1 t2 returns the number of days that are weekend days in the half-open interval [t2,t1) if t1 >= t2, and - diff_weekend_days t2 t1 otherwise.

add_weekdays t 0 returns the next weekday if t is a weekend and t otherwise. Unlike add_days this is done by looping over the count of days to be added (forward or backwards based on the sign), and is O(n) in the number of days to add. Beware, add_weekdays sat 1 or add_weekdays sun 1 both return the next tue, not the next mon. You may want to use following_weekday if you want the next following weekday, following_weekday (fri|sat|sun) would all return the next mon.

add_business_days t ~is_holiday n returns a business day even when n=0. add_business_days ~is_holiday:(fun _ -> false) ... is the same as add_weekdays.

If you don't want to skip Saturday or Sunday, use add_days_skipping.

add_days_skipping t ~skip n adds n days to t, ignoring any date satisfying skip, starting at the first date at or after t that does not satisfy skip. For example, if skip t = true, then add_days_skipping t ~skip 0 > t.

add_business_days and add_weekdays are special cases of add_days_skipping.

the following returns a closed interval (endpoints included)

first_strictly_after t ~on:day_of_week returns the first occurrence of day_of_week strictly after t.

is_leap_year ~year returns true if year is considered a leap year

The starting date of the UNIX epoch: 1970-01-01

gen_incl d1 d2 generates dates in the range between d1 and d2, inclusive, with the endpoints having higher weight than the rest. Raises if d1 > d2.

gen_uniform_incl d1 d2 generates dates chosen uniformly in the range between d1 and d2, inclusive. Raises if d1 > d2.