Hledger.Data.Dates

Date parsing and utilities for hledger.

For date and time values, we use the standard Day and UTCTime types.

A SmartDate is a date which may be partially-specified or relative. Eg 2008/12/31, but also 2008/12, 12/31, tomorrow, last week, next year. We represent these as a triple of strings like ("2008","12",""), ("","","tomorrow"), ("","last","week").

A DateSpan is the span of time between two specific calendar dates, or an open-ended span where one or both dates are unspecified. (A date span with both ends unspecified matches all dates.)

An Interval is ledger's reporting interval - weekly, monthly, quarterly, etc.

Documentation

showDate :: Day -> String

getCurrentDay :: IO Day

elapsedSeconds :: Fractional a => UTCTime -> UTCTime -> a

splitSpan :: Interval -> DateSpan -> [DateSpan]

Split a DateSpan into one or more consecutive spans at the specified interval.

splitspan :: (Day -> Day) -> (Day -> Day) -> DateSpan -> [DateSpan]

daysInSpan :: DateSpan -> Maybe Integer

Count the days in a DateSpan, or if it is open-ended return Nothing.

spanContainsDate :: DateSpan -> Day -> Bool

Does the span include the given date ?

parsePeriodExpr :: Day -> String -> (Interval, DateSpan)

Combine two datespans, filling any unspecified dates in the first with dates from the second.

Parse a period expression to an Interval and overall DateSpan using the provided reference date, or raise an error.

spanFromSmartDateString :: Day -> String -> DateSpan

Convert a single smart date string to a date span using the provided reference date, or raise an error.

spanFromSmartDate :: Day -> SmartDate -> DateSpan

showDay :: Day -> String

fixSmartDateStr :: Day -> String -> String

Convert a smart date string to an explicit yyyy/mm/dd string using the provided reference date, or raise an error.

fixSmartDateStrEither :: Day -> String -> Either ParseError String

A safe version of fixSmartDateStr.

fixSmartDate :: Day -> SmartDate -> Day

Convert a SmartDate to an absolute date using the provided reference date.

prevday :: Day -> Day

parsedatetimeM :: String -> Maybe LocalTime

Parse a couple of date-time string formats to a time type.

parsedateM :: String -> Maybe Day

Parse a couple of date string formats to a time type.

parsedatetime :: String -> LocalTime

Parse a date-time string to a time type, or raise an error.

parsedate :: String -> Day

Parse a date string to a time type, or raise an error.

parsetimewith :: ParseTime t => String -> String -> t -> t

Parse a time string to a time type using the provided pattern, or return the default.

smartdate :: GenParser Char st SmartDate

Parse a date in any of the formats allowed in ledger's period expressions, and maybe some others:

 2004
 2004/10
 2004/10/1
 10/1
 21
 october, oct
 yesterday, today, tomorrow
 (not yet) this/next/last week/day/month/quarter/year

Returns a SmartDate, to be converted to a full date later (see fixSmartDate). Assumes any text in the parse stream has been lowercased.

smartdateonly :: GenParser Char st SmartDate

Like smartdate, but there must be nothing other than whitespace after the date.

validMonth :: String -> Bool

validDay :: String -> Bool

validYear :: String -> Bool

yyyymmdd :: GenParser Char st SmartDate

ymd :: GenParser Char st SmartDate

ym :: GenParser Char st SmartDate

y :: GenParser Char st SmartDate

d :: GenParser Char st SmartDate

md :: GenParser Char st SmartDate

month :: GenParser Char st SmartDate

mon :: GenParser Char st SmartDate

yesterday :: GenParser Char st SmartDate

tomorrow :: GenParser Char st SmartDate

today :: GenParser Char st SmartDate

lastthisnextthing :: GenParser Char st SmartDate

periodexpr :: Day -> GenParser Char st (Interval, DateSpan)

intervalanddateperiodexpr :: Day -> GenParser Char st (Interval, DateSpan)

intervalperiodexpr :: GenParser Char st (Interval, DateSpan)

dateperiodexpr :: Day -> GenParser Char st (Interval, DateSpan)

periodexprinterval :: GenParser Char st Interval

periodexprdatespan :: Day -> GenParser Char st DateSpan

doubledatespan :: Day -> GenParser Char st DateSpan

fromdatespan :: Day -> GenParser Char st DateSpan

todatespan :: Day -> GenParser Char st DateSpan

justdatespan :: Day -> GenParser Char st DateSpan

mkdatespan :: String -> String -> DateSpan