darcs-2.11.0: a distributed, interactive, smart revision control system

Safe HaskellNone






getIsoDateTime :: IO String

The current time in the format returned by showIsoDateTime

readUTCDate :: String -> CalendarTime

Read/interpret a date string, assuming UTC if timezone is not specified in the string (see readDate) Warning! This errors out if we fail to interpret the date

parseDate :: Int -> String -> Either ParseError MCalendarTime

Parse a date string, assuming a default timezone if the date string does not specify one. The date formats understood are those of showIsoDateTime and dateTime

getLocalTz :: IO Int

Return the local timezone offset from UTC in seconds

englishDateTime :: CalendarTime -> CharParser a CalendarTime

In English, either a date followed by a time, or vice-versa, e.g,

  • yesterday at noon
  • yesterday tea time
  • 12:00 yesterday

See englishDate and englishTime Uses its first argument as now, i.e. the time relative to which yesterday, today etc are to be interpreted

englishInterval :: CalendarTime -> CharParser a TimeInterval

English expressions for intervals of time,

  • before tea time (i.e. from the beginning of time)
  • after 14:00 last month (i.e. till now)
  • between last year and last month
  • in the last three months (i.e. from then till now)
  • 4 months ago (i.e. till now; see englishAgo)

englishLast :: CalendarTime -> CharParser a (CalendarTime, CalendarTime)

Durations in English that begin with the word "last", E.g. "last 4 months" is treated as the duration between 4 months ago and now

iso8601Interval :: Int -> CharParser a (Either TimeDiff (MCalendarTime, MCalendarTime))

Intervals in ISO 8601, e.g.,

  • 2008-09/2012-08-17T16:30
  • 2008-09/P2Y11MT16H30M
  • P2Y11MT16H30M/2012-08-17T16:30

See iso8601Duration

iso8601Duration :: CharParser a TimeDiff

Durations in ISO 8601, e.g.,

  • P4Y (four years)
  • P5M (five months)
  • P4Y5M (four years and five months)
  • P4YT3H6S (four years, three hours and six seconds)

cleanLocalDate :: String -> IO String

Convert a date string into ISO 8601 format (yyyymmdd variant) assuming local timezone if not specified in the string Warning! This errors out if we fail to interpret the date

resetCalendar :: CalendarTime -> CalendarTime

Set a calendar to UTC time any eliminate any inconsistencies within (for example, where the weekday is given as Thursday, but this does not match what the numerical date would lead one to expect)

data MCalendarTime

An MCalenderTime is an underspecified CalendarTime It is used for parsing dates. For example, if you want to parse the date '4 January', it may be useful to underspecify the year by setting it to Nothing. This uses almost the same fields as CalendarTime, a notable exception being that we introduce mctWeek to indicate if a weekday was specified or not


toMCalendarTime :: CalendarTime -> MCalendarTime

Trivially convert a CalendarTime to a fully specified MCalendarTime (note that this sets the mctWeek flag to False

unsafeToCalendarTime :: MCalendarTime -> CalendarTime

Returns the first CalendarTime that falls within a MCalendarTime This is only unsafe in the sense that it plugs in default values for fields that have not been set, e.g. January for the month or 0 for the seconds field. Maybe we should rename it something happier. See also resetCalendar

unsetTime :: CalendarTime -> CalendarTime

Zero the time fields of a CalendarTime