Temporal.PlainYearMonth

plainYearMonth :: Int -> Int -> Maybe PlainYearMonth

Construct from year and month (1–12). Returns Nothing for invalid months.

fromString :: String -> Maybe PlainYearMonth

Parse an ISO 8601 year-month string (e.g. "2024-03"). Returns Nothing for invalid strings.

getYear :: PlainYearMonth -> Int

Calendar year.

getMonth :: PlainYearMonth -> Int

Month of the year (1–12).

getMonthCode :: PlainYearMonth -> String

Month code string (e.g. "M03" for March). Useful for non-ISO calendars.

getDaysInMonth :: PlainYearMonth -> Int

Number of days in this month (28–31).

getDaysInYear :: PlainYearMonth -> Int

Number of days in this year (365 or 366).

getMonthsInYear :: PlainYearMonth -> Int

Always 12 for the ISO calendar.

getInLeapYear :: PlainYearMonth -> Boolean

Whether this year is a leap year.

with :: { month :: Int, year :: Int } -> PlainYearMonth -> Maybe PlainYearMonth

Create a modified copy with the given year and month. Returns Nothing if the result would be invalid.

add :: Duration -> PlainYearMonth -> Maybe PlainYearMonth

Add a duration (only year and month components are meaningful). Returns Nothing on overflow.

subtract :: Duration -> PlainYearMonth -> Maybe PlainYearMonth

Subtract a duration. Returns Nothing on overflow.

type PlainYearMonthDiffOptions = { largestUnit :: DateUnit, roundingIncrement :: Int, roundingMode :: RoundingMode, smallestUnit :: DateUnit }

Options for since and until. Default: largest unit is Years, smallest unit is Months.

defaultPlainYearMonthDiffOptions :: PlainYearMonthDiffOptions

since :: PlainYearMonthDiffOptions -> PlainYearMonth -> PlainYearMonth -> Duration

since opts a b returns the duration from b to a.

until :: PlainYearMonthDiffOptions -> PlainYearMonth -> PlainYearMonth -> Duration

until opts a b returns the duration from a to b.

since' :: PlainYearMonth -> PlainYearMonth -> Duration

since' a b — duration from b to a with default options.

until' :: PlainYearMonth -> PlainYearMonth -> Duration

until' a b — duration from a to b with default options.

toPlainDate :: Int -> PlainYearMonth -> Maybe PlainDate

Convert to a PlainDate by specifying a day. Out-of-range days are constrained — e.g. toPlainDate 31 on February yields Feb 28 or 29. Returns Nothing for truly invalid values.

toString :: PlainYearMonth -> String

Serialize to an ISO 8601 year-month string (e.g. "2024-03").

data PlainYearMonth

A year and month without a day component (e.g. 2024-03).

Useful for representing months in a calendar UI or credit card expiry dates.

Instances

• Eq PlainYearMonth
• Ord PlainYearMonth
• Show PlainYearMonth

data PlainDate

A calendar date without a time component or time zone (e.g. 2024-03-15).

Use PlainDate for birthdays, holidays, and other dates where time of day is irrelevant. Do not use for scheduling events — use ZonedDateTime instead.

Instances

• Eq PlainDate
• Ord PlainDate
• Show PlainDate

data Duration

A length of time expressed as a combination of date and time components (years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds). All components must share the same sign.

Durations are unbalanced — { hours: 36 } is not automatically converted to { days: 1, hours: 12 }. Use round to balance.

Eq compares component-by-component (not total elapsed time), so { hours: 1 } is not equal to { minutes: 60 }.

Instances

• Eq Duration
• Show Duration