February 13, 2009

Do you remember that song from Sesame Street? The lyrics were so catchy that very few people who grew up watching it have forgotten the song. You don’t even need to look up the lyrics, everyone knows them even if they’ve never watched the show.

1,2,3,4,5… 6,7,8,9,10… 11,12!

If you’re not aware, all UNIX and UNIX-like operating systems keep their time in a format known as “epoch time”. This is the number of seconds since January 1, 1970 00:00:00 GMT. Regardless of your timezone, your UNIX machine should show the same number of seconds as every other UNIX machine in the world. This clock is based off of GMT, and your local timezone settings simply interpret this epoch time based on your local timezone.

So what’s that have to do with the price of beans?

Well, today is an interesting day for the epoch timestamp. Friday, February 13 2009 at 23:31:30 GMT, the epoch timestamp will read 1234567890.

So how can you be sure that your UNIX (or windows machine) has accurate time? Well, if you have a SoftLayer server, you can simply point your ntp client to “servertime.service.softlayer.com”. This traffic then passes over the back-end private network, which has unlimited bandwidth, and you won’t consume your precious public-facing bandwidth to keep your server’s time accurate to within milliseconds. Just like every other NTP server on the internet, ours sync up constantly throughout the day with various atomic clocks around the world. You can’t get much more accurate than that, at least without having your own little chunk of the radioactive element cesium inside your computer. Incidentally, this is the same thing that makes your GPS system work. Hundreds of satellites overhead, which are basically nothing more than cesium clocks with transmitters that constantly broadcast the current time.

It’s just another one of those cool things that we do for our customers to help them get the most out of their server without having all the bare essentials stack up against their monthly bandwidth allocation.