compareMonthDays

Unreleased

Not in @northguild/gmt 1.20.0 on npm yet. It is on main and ships in the next release.

Signature

compareMonthDays(a: string, b: string): number | null

Compare two month-day strings (--MM-DD, or MM-DD) in calendar order: month first, then day.

• Accepts both input forms, so 12-25 and --12-25 compare equal.
• The year is not part of a month-day: --02-29 sorts between --02-28 and --03-01. (Temporal has no PlainMonthDay.compare; this compares the matching PlainDates in the leap reference year 1972, as the note on PlainMonthDay.prototype.valueOf directs.)
• Returns null if either input is invalid or not in the ISO calendar.

Parameters

Parameter	Type	Description
a	string	month-day string
b	string	month-day string

Returns

-1, 0, or 1, or null on invalid input

Examples

import { compareMonthDays } from "@northguild/gmt/plain/compare";

compareMonthDays("--01-01", "--12-31") // -1

a

b

output

 

Source

plain/compare/compareMonthDays.ts