Days of the year: Temporal's PlainMonthDay — plain_month

A plain_month_day() is a month and day with no year, such as a birthday, in the ISO 8601 calendar, stored as an integer month * 32 + day. Temporal keeps the day valid in a reference year, 1972, so February 29 is a plain_month_day(). The constructor is Temporal.PlainMonthDay and Temporal.PlainMonthDay.from() in one: it reads fields, strings or a plain_date() or plain_date_time().

Usage

plain_month_day(
  month,
  day = NULL,
  ...,
  month_code = NULL,
  year = NULL,
  overflow = "constrain"
)

Arguments

month: The month (1 to 12), or a string in ISO 8601 form ("03-14", "--03-14", "0314", or a full date or date-time whose year and time are ignored), or a plain_month_day(), plain_date() or plain_date_time() to convert. May be replaced by month_code.
day: The day of the month, when month is a number.
...: Must be empty.
month_code: The month as "M01" to "M12", instead of month.
year: A year in which the day must exist; without it the reference year 1972, a leap year, is used.
overflow: "constrain" (the default) clamps month and day, "reject" raises a zutempo_range_error.

Value

A plain_month_day() vector.

Members

Every member of Temporal.PlainMonthDay in the pinned specification (inst/spec/PINS) and the R function that implements it:

Temporal	R
`new Temporal.PlainMonthDay()`	`plain_month_day()`
`Temporal.PlainMonthDay.from()`	`plain_month_day()`
`.calendarId`	`calendar_id()`
`.monthCode`	`month_code()`
`.day`	`day()`
`.with()`	`temporal_with()`
`.equals()`	`temporal_equals()`
`.toString()`	`temporal_to_string()`
`.toLocaleString()`	none: ECMA-402 (locale formatting) is out of scope
`.toJSON()`	none: format() covers it
`.valueOf()`	none: throws in JavaScript; no R counterpart
`.toPlainDate()`	`temporal_to_plain_date()`

Examples

plain_month_day("02-29")
#> <zutempo_plain_month_day[1]>
#> [1] 02-29
plain_month_day(2, 29, year = 2025)
#> <zutempo_plain_month_day[1]>
#> [1] 02-28
plain_month_day(plain_date("2026-03-14"))
#> <zutempo_plain_month_day[1]>
#> [1] 03-14
temporal_to_plain_date(plain_month_day("02-29"), year = 2025)
#> <zutempo_plain_date[1]>
#> [1] 2025-02-28