Leap Second Problems

RT @arstechnica

“Almost exactly 24 hours ago, the Internet faced the most recent one. It didn't go so well. Headlines have varied—calling the incident "Y2K 2.0," declaring that the "Internet died," or simply saying it, "Gave the Internet a Really Bad Headache." Hyperbolic? Sure, but the following sites did confirm leap second-related outages…”

Google and the Leap Second

Soon after the advent of ticking clocks, scientists observed that the time told by them (and now, much more accurate clocks), and the time told by the Earth's position were rarely exactly the same. It turns out that being on a revolving imperfect sphere floating in space, being reshaped by earthquakes and volcanic eruptions, and being dragged around by gravitational forces makes your rotation somewhat irregular. Who knew?

These fluctuations in Earth’s rotational speed mean that even very accurate clocks, like the atomic clocks used by global timekeeping services, occasionally have to be adjusted slightly to bring them in line with “solar time.” There have been 24 such adjustments, called “leap seconds,” since they were introduced in 1972. Their effect on technology has become more and more profound as people come to rely on fast, accurate and reliable technology.

Image credit: gunnar3000/Pond5.com

If You Think Today's Date is 1/1/11

You may be interested to note the time will be 11:11:11 in a few minutes.

In fact, if you have a precise clock, the time will actually pass through 11:11:11.1111...  at 1/9 second past.

I think today's date is  Sat 2011-01-01.  Granted, there are still a lot of ones!

RFC 3331 and Bash

I've mentioned ISO 8601 here.  As of yesterday, I've started aliasing the shell date(1) command to issue an ISO 8601, RFC 3339 format with the day of the week prepended.

Here's how date(1) normally looks.

Tue Mar 30 06:09:20 EDT 2010

With the bash alias

alias date="date '+%a %Y-%m-%d %H:%M:%S %z'"

The output looks like this…

Tue 2010-03-30 06:06:37 -0400

As you can probably tell, date and time stamps are a big deal with me.

Actually this mostly comes into play inside Emacs where I constantly use macros that insert date and time stamps.

Sadly, the latter format is one character longer than the other style.  The two-digit month is one byte shorter than the three-character abbreviation.  However, the time zone indicator -0400 is two longer than the three-character time zone abbreviation.  Ah well, the cost or progress.

Happy Vernal Equinox!

20 Mar 2010 at 13:32 EDT.

Palindrome Day

Whether you follow the proper ISO 8601 format  20100102 or the improper format 01022010, today's date is a palindrome.  Enjoy!

World Clock

This is an excellent GUI World Clock.

ISO 8601

So what is the actual ISO date format? It's ISO 8601.

Basically, the current time would be: 2009-08-15 23:53:00 -0400

Wikipedia Page
ISO Article

High Precision Strontium Clock

Rick U at work first told me there was some interesting work being done with a strontium lattice.  Then was this recent story from NIST regarding work on a high-precision atomic clock based on strontium.

Here's the actual story on work being done on ultra-cold strontium in the Ye Group at Colorado.

Interesting Time Stamp

Hey, another interesting UNIX timestamp is upon us (thanks to a note from Simon on the dreaded Facebook).  It will soon be 1234567890 seconds since the UNIX epoch of 1 Jan 1970 0:00 UT, and on Friday the thirteenth no less!

>>> time.ctime(1234567890)

'Fri Feb 13 18:31:30 2009'

Remeber when the timestamp was 1000000000?

>>> time.ctime(1000000000)

'Sat Sep  8 21:46:40 2001'

(The times I've shown here are Eastern Standard), i.e., 

>>> time.ctime(0)

'Wed Dec 31 19:00:00 1969'

and of course these are from the Python interpreter.

As always, we live in interesting times!

P.S.  And I can't talk about time stamps without reminding us of UNIX's equivalent of Y2K, when the timestamp reaches the maximum value of a 32-bit signed integer (i.e., a 31-bit number):

>>> time.ctime(0x7fffffff)

'Mon Jan 18 22:14:07 2038'

Mark your calendar!

Summer Solstice at 23:59 UTC!

Happy Summer Solstice! It occurs today 20 June 2008 at 23:59 UTC = 19:59 EDT, almost exactly at 0:00!