Tag Archives: calendar

Happy Imbolic

Ever wonder where Groundhog day comes from? Notice that it’s about 1/2 way to Spring?

We are now halfway between the Winter Solstice (December 21) and the Vernal or Spring Equinox (March 20).  It’s called a cross-quarter day is known as Imbolc (or some variation of that spelling) in the Celtic world  It’s also a modern Neopagan celebration and part of the Wheel of the Year.

Imbolc is most commonly celebrated on February 2 (same as Groundhog Day and Candlemas on the Christian calendar) but it actually occurs, according to the position of the Sun on the ecliptic, at 11:20 pm EST on Thursday, February 3 this year.

This cross-quarter day has been known since antiquity – a 5,000 year-old Neolithic passage tomb at the Hill of Tara in County Meath, Ireland has an alignment with sunrise on Imbolc.  The word Imbolc comes from the Celtic i mbolg or “in the belly” referring to pregnant ewes who soon give birth to spring lambs.  It was viewed as the start of spring (even though snow may yet be on the ground), a time for weather prognostication, and to watch for animals emerging from their winter dens (sound familiar?  Groundhog Day has its roots in similar Germanic pagan beliefs).

Read the rest over at Hudson Valley Geologist.

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.