Tag Archives: timezone

Here comes the Leap Second

The tzdata update which includes the leap second for Ubuntu just came down the pipe:

Version 2012b-0ubuntu0.11.10:

* New upstream release 2012b:
– Update DST rules for Chile (LP: #948328), Armenia, Samoa, Cuba,
– Fix historic DST rules for Canada.
– Add leap seconds for June 2012.

This is why you need to apply updates regularly, and make sure you are on a supported distro. I’m very curious how mobile is going to handle this, as this will be the first leap second addition any of the major Smart Phone OSes has ever had to deal with.

Time is Saved

The Electronic Frontier Foundation just won the most important legal case you didn’t know about this year, and protected the existence of the Olson Time Zone Database.

San Francisco – The Electronic Frontier Foundation (EFF) is pleased to announce that a copyright lawsuit threatening an important database of time zone information has been dismissed. The astrology software company that filed the lawsuit, Astrolabe, has also apologized and agreed to a ‘covenant not to sue’ going forward, which will help protect the database from future baseless legal actions and disruptions.

Surprisingly enough, the world’s timezones aren’t kept by an inter-government committee, but by a few intrepid volunteers. This was really important to protect, and you should consider becoming a member of the EFF to protect these kinds of things in the future.

Who knew that timezone history could be so compelling

I finally decided to find the base zoneinfo files that all timezone data in computing is computed from.  It turns out that the uncompiled files have an incredible amount of history embedded in them, including a number of really interesting stories.  Here are some exceprts:

# From Paul Eggert (2001-05-30):
# Howse writes that Alaska switched from the Julian to the Gregorian calendar,
# and from east-of-GMT to west-of-GMT days, when the US bought it from Russia.
# This was on 1867-10-18, a Friday; the previous day was 1867-10-06 Julian,
# also a Friday.  Include only the time zone part of this transition,
# ignoring the switch from Julian to Gregorian, since we can’t represent
# the Julian calendar.

# Since 1970, most of Indiana has been like America/Indiana/Indianapolis,
# with the following exceptions:
# – Gibson, Jasper, Lake, LaPorte, Newton, Porter, Posey, Spencer,
#   Vandenburgh, and Warrick counties have been like America/Chicago.
# – Dearborn and Ohio counties have been like America/New_York.
# – Clark, Floyd, and Harrison counties have been like
#   America/Kentucky/Louisville.
# – Crawford, Daviess, Dubois, Knox, Martin, Perry, Pike, Pulaski, Starke,
#   and Switzerland counties have their own time zone histories as noted below.
# Shanks partitioned Indiana into 345 regions, each with its own time history,
# and wrote “Even newspaper reports present contradictory information.”
# Those Hoosiers!  Such a flighty and changeable people!
# Fortunately, most of the complexity occurred before our cutoff date of 1970.
# Other than Indianapolis, the Indiana place names are so nondescript
# that they would be ambiguous if we left them at the `America’ level.
# So we reluctantly put them all in a subdirectory `America/Indiana’.

# Shanks writes that Michigan started using standard time on 1885-09-18,
# but Howse writes (pp 124-125, referring to Popular Astronomy, 1901-01)
# that Detroit kept
#    local time until 1900 when the City Council decreed that clocks should
#    be put back twenty-eight minutes to Central Standard Time.  Half the
#    city obeyed, half refused.  After considerable debate, the decision
#    was rescinded and the city reverted to Sun time.  A derisive offer to
#    erect a sundial in front of the city hall was referred to the
#    Committee on Sewers.  Then, in 1905, Central time was adopted
#    by city vote.
# This story is too entertaining to be false, so go with Howse over Shanks.

What’s also kind of interesting is the time offsets prior to standardization

# Zone    NAME        GMTOFF    RULES    FORMAT    [UNTIL]
Zone America/New_York    -4:56:02 –    LMT    1883 Nov 18 12:03:58
Zone America/Chicago    -5:50:36 –    LMT    1883 Nov 18 12:09:24
Zone America/Los_Angeles -7:52:58 –    LMT    1883 Nov 18 12:07:02

This has now inspired me to request Seize the Daylight from our local library.