Date.is_leap_day seems wrong

[twopir]

utop [21]: Date.is_leap_year 2000;;
- : bool = true
utop [22]: Date.is_leap_day (Date.make 2000 2 29);;
- : bool = false

calendar/src/date.ml

Line 212 in a447a88

is_leap_year (year d) && month d = Feb && day_of_month d = 24

This seems to just be defined incorrectly.

[twopir]

Or I could read the FAQ — sorry!

calendar/calendarFAQ-2.6.txt

Line 663 in a447a88

It is 24 February!

[Drup]

The behavior may be correct, but it should be explained in the documentation of the function, not lost in the FAQ that most people don't know exist. :)