Localize version 0..28.0

[0.28.0] — May 9th, 2026

Behaviour Change

• Localize.Interval.to_string/3 Date intervals (style :date, the default) now resolve their skeleton per-locale instead of using a hard-coded locale-independent mapping. The interval looks up Localize.DateTime.Format.date_formats(locale_id)[format] — the same mapping Localize.Date.to_string/2 uses — so date intervals follow the same conventions as single dates for the same :format. Visible effect on locales whose single-Date skeletons differ from the previous Interval table — most notably:

  • ja :medium is now numeric ("2012/01/05～2012/01/06"), aligning with single Date :medium ("2012/01/05"); was previously the abbreviated month form "2012年1月5日～6日". The richer Japanese-character form is now :long (matching single Date :long).
  • de :medium is now numeric ("15.01.2022 – 20.03.2022"); was previously the abbreviated month form. To get "15. Jan. – 20. März 2022" request the :yMMMd skeleton explicitly.
  • en :long uses full month name with no weekday ("January 5, 2012 – January 6, 2012"); was previously the :yMMMEd form "Thu, Jan 5 – Fri, Jan 6, 2012". The weekday now appears at :full. Per-locale skeletons that aren't shipped in CLDR's interval_formats data fall back to formatting each endpoint with Localize.Date.to_string/2 and joining via the locale's interval_format_fallback template. Non-:date styles (:month, :month_and_day, :year_and_month) remain locale-independent — they describe a deliberate field selection unrelated to standard date styles. The static Localize.Interval.date_styles/0 no longer includes a :date entry.

Bug Fixes

• Strip zone token for NaiveDateTime too in Localize.Time.to_string/2 since they also do not have a time zone field. Relates to #22.

• Fix Localize.Interval.to_string/3 silently ignoring the :date_format option on Date-only intervals. The option now overrides :format on the date axis, mirroring the precedence used for :time_format on time intervals. Relates to #22.

• Fix Localize.Interval.to_string/3 raising Localize.DateTimeIntervalFormatError when called with format: :full on a Date interval. Relates to #22.

• Localize.Utils.Math.sqrt/2 now respects the current Decimal.Context.get/0 precision when called with a Decimal — the result is rounded to the configured precision and Newton's-method convergence scales accordingly.

• Added the test suite for Localize.Utils that are derived from the Cldr.Util equivalents.