I hope this is useful to someone as I couldn't find it anywhere else on the net.
Output Format is Sun, 03 Apr 2011 12:42:04 GMT
11:48 am on Apr 3, 2011 (gmt 0)
Note that GMT officially ceased to exist in 1972.
The base time zone for the planet is now UTC, which for most intents and purposes is numerically equivalent but is not at all the same thing.
The problem is that UK clocks show UTC+0000 in Winter and UTC+0100 in Summer. That is, while the UK uses a zone numerically equivalent to GMT in the Winter, UK clocks use a zone which is numerically equivalent to GMT+1 in Summer.