[GoLUG] cal 9 1752 and the Gregorian calendar revision

[David Billsbrough]

Kyle wrote:

> And *that* is one of the craziest things I have learned in a while.
> The Western countries have one calendar, and the Eastern countries
> have another. They just happen to coincide for several centuries,
> partly out of design. After 28 February 2800, the East and West will
> be off by one day, and someone will need to do something about it
> again.


Hello Super-Kyle,

Your research skills are very good ... now rest up for three days and then explain to us
*all* about how modern hardware (computers and GPS units) keeps time and represents it!

   https://en.wikipedia.org/wiki/Year_2038_problem

it appears that we will always have a 'best if used by' time limit on current/future technology.

  :-)

That stuff and also floating point numbers are all about keeping your 'bits' in *correct* order!

   https://www.geeksforgeeks.org/ieee-standard-754-floating-point-numbers/


also on a lighter note  ...   that give *us* a little more than a half-millennium to find another
smart Serbian that good with date math!

regards,

David
--
David Billsbrough -- Amateur Radio Callsign: KC4ZVW
Chuluota, Florida * grid square: EL98kp * https://www.kc4zvw.us/


-----Original Message-----
From: Kyle Terrien <kyle at terren.us>
Sent: Mar 6, 2025 11:22 PM
To: <golug at golug.org>
Subject: [GoLUG] cal 9 1752 and the Gregorian calendar revision

During GoLUG yesterday, I dared everyone to run &lsquo;cal 9 1752&rsquo;. No,
this is not a prank or computer cracking trick. This is the month
that England and her colonies switched from the Julian Calendar to the
Gregorian Calendar. 11 days were skipped to catch up with the
Gregorian Calendar.

September 1752
S M Tu W Th F S
1 2 14 15 16
17 18 19 20 21 22 23
24 25 26 27 28 29 30

I did a little bit of digging and went down a historical rabbit hole.

The Gregorian Calendar[1] is a calendar revision promulgated by Pope
Gregory XIII in 1582. It replaced the Julian calendar, which has leap
years every 4 years. In the Gregorian system, years divisible by 100
are not leap years unless they are also divisible by 400, for a grand
cycle of 400 years. This extra rule was invented to align the
calendar better with the summer solstice and make the calculation of
Easter more reliable.

  {trimmed}

--Kyle

[1]: https://en.wikipedia.org/wiki/Gregorian_calendar
[2]: https://en.wikipedia.org/wiki/Date_of_Easter
[3]: https://en.wikipedia.org/wiki/Adoption_of_the_Gregorian_calendar#Timeline
[4]: https://en.wikipedia.org/wiki/East%E2%80%93West_Schism
[5]: https://en.wikipedia.org/wiki/Revised_Julian_calendar
[6]: https://en.wikipedia.org/wiki/Old_Calendarists