Posts Tagged ‘leap second’

Yep, you read it correct. New Year will be indeed one second late. If you just uttered WTF, you need to know about leap seconds. Righto! There are leap seconds just like there are leap years.

Remember as a kid you studied that a full revolution of earth around the sun is called a year and a full rotation of earth about its axis is called a day. And also that the solar year (time for one complete revolution) is 6 hours more than 365 days. So we have to add an extra day in February to compensate for this differential every 4 years.

Well leap seconds have a similar background. As you might be aware these days time is measured in terms of oscillations of Caesium-133 crystal. Now as it turns out, the crystal is more precise than earth’s rotation. Earth’s rotation is affected by a number of factors like solar winds, motion of masses inside earth etc. So we have a time differential, which keeps on accumulating with each day.

When this difference reaches a certain limit (i.e. close to 1 sec), it has to be corrected and this is when a leap second is added to the time. The total differential accumulated over the entire year is 0.6 so a leap second is generally added after 18 months.

The International Earth Rotation and Reference Systems Service takes care of all the complex mathematics and science for you and announces when a leap second is going to be added. Typically when a leap second is added the clock moves from 23:59:59 to 23:59:60 before striking 00:00:00. As it turns out a leap second will be added at 23:59:59 UTC on 31st December 2008. Here is the official announcement

So what do you need to do? Well computers and cellphones will adjust automatically via NTP and other means, and I suppose you wont be bothered adjusting your wrist watch to the closest second. So go and Party, just wait another second before you wish if you want to be precise and/or if your life depends on it!. If you are interested in catching the clock turn 23:59:60 these are some of your best bets or have a look here

Here in India we would have already wished new year, but people living in timezones that are behind UTC (and including UTC) would have to postpone the wishes for another second. Or you can countdown to -1 😉 or perhaps ..3, 2, 1, leapsecond, 0, Happy New Year!

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