Calendar dates: Temporal's PlainDate — plain

A plain_date() is a calendar date in the ISO 8601 calendar with no time of day and no time zone, stored as an integer count of days since 1970-01-01. The constructor is Temporal.PlainDate and Temporal.PlainDate.from() in one: it reads fields, strings or another zutempo value.

Usage

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

plain_date_compare(x, y)

Arguments

year: The year, or a string in ISO 8601 form ("2026-01-31", a date-time whose time is ignored, or a year with a sign and six digits such as "+275760-09-13"), or a plain_date(), plain_date_time(), zoned_date_time(), Date, POSIXct or POSIXlt value to convert. A zoned or POSIXt value gives its date in its own zone.
month, day: The month (1 to 12) and day of the month, when year is a number. month may be replaced by month_code.
...: Must be empty.
month_code: The month as "M01" to "M12", instead of month.
overflow: "constrain" (the default) clamps month and day to their valid ranges, "reject" raises a zutempo_range_error for them.
x, y: plain_date() values or strings, for plain_date_compare().

Value

A plain_date() vector; plain_date_compare() returns an integer vector of -1, 0 and 1.

Details

Dates run from -271821-04-19 to +275760-09-13. A result outside that range is a zutempo_range_error, never NA.

Members

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

Temporal	R
`new Temporal.PlainDate()`	`plain_date()`
`Temporal.PlainDate.from()`	`plain_date()`
`Temporal.PlainDate.compare()`	`plain_date_compare()`
`.calendarId`	`calendar_id()`
`.era`	`era()`
`.eraYear`	`era_year()`
`.year`	`year()`
`.month`	`month()`
`.monthCode`	`month_code()`
`.day`	`day()`
`.dayOfWeek`	`day_of_week()`
`.dayOfYear`	`day_of_year()`
`.weekOfYear`	`week_of_year()`
`.yearOfWeek`	`year_of_week()`
`.daysInWeek`	`days_in_week()`
`.daysInMonth`	`days_in_month()`
`.daysInYear`	`days_in_year()`
`.monthsInYear`	`months_in_year()`
`.inLeapYear`	`in_leap_year()`
`.toPlainYearMonth()`	`temporal_to_plain_year_month()`
`.toPlainMonthDay()`	`temporal_to_plain_month_day()`
`.add()`	`temporal_add()`
`.subtract()`	`temporal_subtract()`
`.with()`	`temporal_with()`
`.withCalendar()`	`temporal_with_calendar()`
`.until()`	`temporal_until()`
`.since()`	`temporal_since()`
`.equals()`	`temporal_equals()`
`.toPlainDateTime()`	`temporal_to_plain_date_time()`
`.toZonedDateTime()`	`temporal_to_zoned_date_time()`
`.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

Examples

plain_date("2026-01-31")
#> <zutempo_plain_date[1]>
#> [1] 2026-01-31
plain_date(2026, 2, 31)
#> <zutempo_plain_date[1]>
#> [1] 2026-02-28
plain_date(2026, month_code = "M02", day = 29, overflow = "constrain")
#> <zutempo_plain_date[1]>
#> [1] 2026-02-28
plain_date(c("2026-01-31", NA, "+275760-09-13"))
#> <zutempo_plain_date[3]>
#> [1] 2026-01-31    <NA>          +275760-09-13
plain_date_compare(plain_date("2026-01-31"), "2026-02-01")
#> [1] -1