Calendrical version 1.0.0

[1.0.0] — 2026-07-31

The first stable release, built on Localize 1.0.

Fixed

• Calendrical.Persian.date_from_iso_days/1 computed the month with :math.ceil/1 in one branch and Kernel.ceil/1 in the other, so any date after the 186th day of the Persian year carried a float month back into date_to_iso_days/3. The returned month was truncated and therefore correct, but the intermediate arithmetic ran on floats.

• Specifications that omitted error returns the function can actually make are corrected, so a caller reading the spec now sees every value it can receive. Calendrical.next/3 and previous/3 return {:error, :not_defined}; Calendrical.Julian.year/1, quarter/2 and month/2 return {:error, :invalid_date}; Calendrical.Interval.week/1 returns {:error, :not_defined}; Calendrical.Composite.new/2 returns {:error, :must_be_a_list_of_dates | :no_calendars_configured}; and the astronomical Ecclesiastical functions return {:error, :year_out_of_range}.

Changed

• Requires localize ~> 1.0.

• Year-conversion helpers (Calendrical.Roc.gregorian_year/1, Calendrical.Buddhist.buddhist_year/1, the Indian and Ethiopic equivalents) and the per-calendar date_to_iso_days/3 implementations now guard their arguments with is_integer/1. A non-integer argument raises FunctionClauseError rather than silently computing a float result.

• Dialyzer runs with the Localize flag set (:error_handling, :unknown, :underspecs, :extra_return, :missing_return). The exclusions in .dialyzer_ignore.exs are documented individually.