BSD-3-Clause licensed by Bjorn Buckwalter
Maintained by [email protected]
This version can be pinned in stack with:leapseconds-announced-2017.1.0.1@sha256:245cdcabb8060cab1bdb19d3a4e253a946db69c1ae636923348c7d3cbd05495b,1431

Module documentation for 2017.1.0.1

Depends on 2 packages(full list with versions):


This libraray provides a static Data.Time.Clock.TAI.LeapSecondTable “containing” the leap seconds announced at library release time. A new version of the library is released every time the International Earth Rotation and Reference Systems Service (IERS) announces a new leap second at

This module is intended to provide a quick-and-dirty leap second solution for one-off analyses concerned only with the past and present (i.e. up until the next as of yet unannounced leap second), or for applications which can afford to be recompiled against an updated library as often as every six months.


Import Data.Time.Clock.AnnouncedLeapSeconds to bring the leap second table lst into scope. Here is a usage example:

import Data.Time
import Data.Time.Clock.TAI
import Data.Time.Clock.AnnouncedLeapSeconds

-- | Convert from UTC to TAI.
utcToTAITime' = utcToTAITime lst
-- | Convert from TAI to UTC.
taiToUTCTime' = taiToUTCTime lst

-- | Add a length of time to a UTC time, respecting leap seconds
--   (as opposed to Data.Time.Clock.addUTCTime).
addUTCTime' :: DiffTime -> UTCTime -> Maybe UTCTime
addUTCTime' dt utc = taiToUTCTime' . addAbsoluteTime dt =<< utcToTAITime' utc


2017.1.0.1 (2017-07)

  • Updated tests for 2017.1 and recent years (thank Dan Burton for filing the issue).

2017.1 (2016-12)

  • Corrected version numbering to reflect API breaking (2017.0.0.1 deprecated).

2017.0.0.1 (2016-12)

  • Ported leapSecondMap of time-1.7.

2017 (2016-06)

  • Added 2017 leap second (2016-12-31T23:59:60Z).

2015.0.0.1 (2015-05)

  • Fix documentation to reflect addition of 2015 leap second.
  • Hide hypothetical leap seconds (prior to 1972-01-01).
  • Add test suite to .cabal.

2015 (2015-01)

  • Added 2015 leap second (2015-06-30T23:59:60Z).

2012 (2012-01)

  • Added 2012 leap second (2012-06-30T23:59:60Z).

2009 (2009-01)

Initial release including all leap seconds up to 2009-01-01.