Module dates 

Calendar days as integers: days since 1970-01-01, in UTC.

UTC rather than local time keeps the standard library sufficient. A due date therefore turns at UTC midnight, a few hours off local midnight.

Functions

day

The day containing a Unix timestamp.

format

YYYY-MM-DD for a day number. Algorithm from https://howardhinnant.github.io/date_algorithms.html#civil_from_days

now

Seconds since the Unix epoch.

parse

Parses YYYY-MM-DD, rejecting dates that do not exist.