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Diffstat (limited to 'lib/kernel/date.mli')
| -rw-r--r-- | lib/kernel/date.mli | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/lib/kernel/date.mli b/lib/kernel/date.mli index 2f632c8..0e86d54 100644 --- a/lib/kernel/date.mli +++ b/lib/kernel/date.mli @@ -14,6 +14,13 @@ val month : t -> int val day : t -> int val weekday : t -> weekday +(** Proleptic Gregorian leap-year test: divisible by 4, except a century year + not divisible by 400. The same rule {!make}/{!days_in_month} already use + internally to admit 29 February -- exposed so a rite can key its own + calendar-reckoning rules (e.g. a kalends-doubling convention) off the + identical, single-sourced definition rather than re-deriving it. *) +val is_leap : int -> bool + (** [to_rata]/[of_rata] expose the underlying day-count (days since 1970-01-01); [of_rata] and [add_days] are unbounded total arithmetic (they may denote a year outside 1583..9999 — only [make] enforces the domain). *) |