Why is GMT the standard for computer time instead of UTC?

Question

It feels to me like everywhere I've seen time related algorithms in programming, GMT was the base time. For example, I was told to always store time in a DB in GMT+00 so that time zone changes don't disrupt anything.

1. Am I right that GMT seems to be the base time zone in software development?

2. If so, why not UTC? Why is it not common to say "UTC+01" instead of "GMT+01" considering that even Unix timestamps are defined from UTC (http://en.wikipedia.org/wiki/Unix_time)

Answer 1

This accepted response is actually wrong. First they are not the same by any means. Second UTC is NOT more closely in line with "true" time based off of earth's rotation, is exactly the opposite. UTC is more precise in terms of 'time' measure. Each second last the same since is based on atomic time and the precision is increidble hight (it would take 30 thousand years to offset one second).

GMT instead tracks earth rotation, since this is not always the same (the earth rotation is slowing down) each second differs. Of course, differs in a really small ammount of time. But for cientific purposes, is a lot more accurate UTC than GMT.

This is the reason why UTC changes +2 seconds every 4/5 years (since earth rotation is slower each second it takes to rotate has to be bigger than UTC), so it follows GMT earth rotation time by less than a second of difference.