[squeak-dev] [ANN] TZ-Olson on SqueakMap

David T. Lewis lewis at mail.msen.com
Tue Mar 12 12:16:46 UTC 2019

TZ-Olson is an Olson time zone database for Squeak. It is now listed
on SqueakMap at http://map.squeak.org and maintained at

See https://en.wikipedia.org/wiki/Tz_database for background and general
information. The class comment for TimeZoneDatabase provides additional

The Squeak Chronology package, especially class DateAndTime, represents time
in terms of magnitude (seconds relative to a Posix or Smalltalk reference
point) and offset from UTC, where the offset allows the DateAndTime to be
displayed relative to a local timezone. When combined with Olson time zone
tables, any instance of DateAndTime may be displayed for another time zone,
and a local time specification in any time zone may be used to create a
DateAndTime instance with correct magnitude.

TZ-Olson is a subset of the original TimeZoneDatabase package for Squeak,
and replaces it for Squeak images beginning with Squeak 5.3.


To show the current time in central Europe:

   DateAndTime now inTimeZoneNamed: 'CET'

To create a DateAndTime for a local time in another time zone, accounting
for daylight savings time changes:

      year: 2013
      month: 3
      day: 31
      hour: 13
      minute: 17
      second: 19
      inTimeZoneNamed: 'CET'

To locate a suitable time zone:

   TimeZoneDatabase grepFor: 'CET'.
   TimeZoneDatabase grepFor: 'Detroit'.

To set the default time zone in the database to match that of your operating system:

   TimeZoneDatabase defaultLocation: 'CET'.
To inspect daylight savings transition times:

   TimeZoneDatabase defaultTimeZone dstTransitionTimes.


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