Module datetime 

The datetime string format.

atproto’s datetime is a subset of both RFC 3339 and ISO 8601, and the interesting part is everything the subset excludes. Every field is zero-padded to a fixed width, the T separator and the Z designator are uppercase only, seconds are mandatory, a timezone is mandatory, and -00:00 — RFC 3339’s “offset unknown” — is refused because ISO 8601 does not have it. The result is a format where two timestamps naming the same instant are the same string far more often than RFC 3339 would give.

Syntax is not the whole check. 1985-13-12T23:20:50.123Z is well formed and names month thirteen, so the calendar is validated too: upstream keeps those cases in a separate datetime_parse_invalid.txt precisely because an implementation that only matches the shape looks green while accepting them.

Enums

DatetimeError

Why a string is not a valid atproto datetime.

Functions

days_before_month 🔒

Days elapsed in the year before the first of month.

days_in_month 🔒

How many days that month holds in that year.

is_leap 🔒

Whether a year is a leap year in the proleptic Gregorian calendar.

range 🔒

Bounds one component, naming it in the error.

render

Writes at in this format: RFC 3339, in UTC, with the Z designator.

validate

Checks a string against the atproto datetime rules, syntax and calendar.