diamond geezer

 Thursday, March 20, 2008

Extreme
Early
Easter
(vernal equinox 05:48 GMT, 20/03/07)

It can't have escaped your notice that there's an early Easter this year. Like, very very early. March 23rd is a ridiculously early date for Easter to fall, but that's the way the calendar works out this year. Oh yes, this is most definitely an Extreme Early Easter.

This year's Easter isn't quite record-breakingly early, but it nearly is. There's not been an Easter this early since 1913, which is nearly a century ago and you won't remember that. There won't be an Easter this early again until 2160, which is more than a century and half away and you definitely won't be around for that. And there won't be an earlier Easter than this until 2285, which is so far into the future that we'll probably have drowned the planet by then. Oh yes, this is most definitely an Extreme Early Easter.

Thanks to to some very complicated ecclesiastical rules involving equinoxes and full moons (which I'll go into tomorrow), Easter Day can fall on any Sunday between March 22nd and April 25th. The period between March 28th and April 20th is the most common, and any Easters outside that range are rather less frequent. This year we're right up at the start of the possible range, on March 23rd, because a couple of unlikely events have combined to create a freak rarity. An Extreme Early Easter.

As a movable feast, Easter feels very wrong when it moves too early. It may be nearly three months since we last had a bank holiday, but somehow mid-March is too early to be having a double bank holiday break. School holidays are also all over the place this year because of the early Easter. Some schools are breaking up today and having the next couple of weeks off, whereas others are waiting until mid-April, when Easter "normally" is, and having their break then. Hell, we've not even put the clocks forward yet. And look at the weather, it's more like winter than spring out there. Actually, maybe there's a reason for that. An Extreme Early Equinox.

Today is the first day of spring* - the vernal equinox. The overhead Sun crossed the equator at 05:48 this morning, and we're now entering into the warm half of the year. Yes really, March 20th, not March 21st, is the first day of spring. Spring used to start on March 21st, certainly a century ago it did, but the shifting equinox means that it'll now always be on March 20th. Well, every year from 2008 until 2044 anyway. I explained all this last year, were you not paying attention?
* yes yes yes, I know, northern hemisphere only

It takes the Earth approximately 365 days, 5 hours and 49 minutes to orbit the Sun, so every year the spring equinox shifts almost 6 hours later than the year before. That's approximately 24 hours later every 4 years, which is then cancelled out by the presence of a February 29th a few weeks before the next spring equinox occurs. But this still leaves the calendar 11 minutes short of reality every year, and this tiny difference shifts the spring equinox approximately three-quarters of an hour earlier every 4 years.

So it's not just Easter that's early this year, it's spring too. An equinox before sunrise on March 20th - it's unheard of. In fact the spring equinox hasn't taken place before 6am on March 20th since 1896. Spring hasn't begun this early since the 19th century! But don't get too excited. The phrase "spring hasn't begun this early since the 19th century" has been true every leap year since 1900, and will continue to be true every leap year until 2024. So our premature spring isn't the reason why Easter is early this year. Our early Easter is a result of something that's happening tomorrow. Come back then and I'll tell you more.

• Spring equinox: what it is and why it moves
• Spring equinox: all the times and dates over 4 centuries
• Spring equinox: nice graphs to show how the date and time change

posted 05:48 :

<< click for Newer posts

click for Older Posts >>

click to return to the main page

...or read more in my monthly archives
Jan24  Feb24  Mar24  Apr24  May24  Jun24  Jul24  Aug24  Sep24  Oct24  Nov24  Dec24
Jan23  Feb23  Mar23  Apr23  May23  Jun23  Jul23  Aug23  Sep23  Oct23  Nov23  Dec23
Jan22  Feb22  Mar22  Apr22  May22  Jun22  Jul22  Aug22  Sep22  Oct22  Nov22  Dec22
Jan21  Feb21  Mar21  Apr21  May21  Jun21  Jul21  Aug21  Sep21  Oct21  Nov21  Dec21
Jan20  Feb20  Mar20  Apr20  May20  Jun20  Jul20  Aug20  Sep20  Oct20  Nov20  Dec20
Jan19  Feb19  Mar19  Apr19  May19  Jun19  Jul19  Aug19  Sep19  Oct19  Nov19  Dec19
Jan18  Feb18  Mar18  Apr18  May18  Jun18  Jul18  Aug18  Sep18  Oct18  Nov18  Dec18
Jan17  Feb17  Mar17  Apr17  May17  Jun17  Jul17  Aug17  Sep17  Oct17  Nov17  Dec17
Jan16  Feb16  Mar16  Apr16  May16  Jun16  Jul16  Aug16  Sep16  Oct16  Nov16  Dec16
Jan15  Feb15  Mar15  Apr15  May15  Jun15  Jul15  Aug15  Sep15  Oct15  Nov15  Dec15
Jan14  Feb14  Mar14  Apr14  May14  Jun14  Jul14  Aug14  Sep14  Oct14  Nov14  Dec14
Jan13  Feb13  Mar13  Apr13  May13  Jun13  Jul13  Aug13  Sep13  Oct13  Nov13  Dec13
Jan12  Feb12  Mar12  Apr12  May12  Jun12  Jul12  Aug12  Sep12  Oct12  Nov12  Dec12
Jan11  Feb11  Mar11  Apr11  May11  Jun11  Jul11  Aug11  Sep11  Oct11  Nov11  Dec11
Jan10  Feb10  Mar10  Apr10  May10  Jun10  Jul10  Aug10  Sep10  Oct10  Nov10  Dec10 
Jan09  Feb09  Mar09  Apr09  May09  Jun09  Jul09  Aug09  Sep09  Oct09  Nov09  Dec09
Jan08  Feb08  Mar08  Apr08  May08  Jun08  Jul08  Aug08  Sep08  Oct08  Nov08  Dec08
Jan07  Feb07  Mar07  Apr07  May07  Jun07  Jul07  Aug07  Sep07  Oct07  Nov07  Dec07
Jan06  Feb06  Mar06  Apr06  May06  Jun06  Jul06  Aug06  Sep06  Oct06  Nov06  Dec06
Jan05  Feb05  Mar05  Apr05  May05  Jun05  Jul05  Aug05  Sep05  Oct05  Nov05  Dec05
Jan04  Feb04  Mar04  Apr04  May04  Jun04  Jul04  Aug04  Sep04  Oct04  Nov04  Dec04
Jan03  Feb03  Mar03  Apr03  May03  Jun03  Jul03  Aug03  Sep03  Oct03  Nov03  Dec03
 Jan02  Feb02  Mar02  Apr02  May02  Jun02  Jul02 Aug02  Sep02  Oct02  Nov02  Dec02