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What would you recommend using between a datetime and a timestamp field, and why? (using mysql). I'm working with php on the server side.

I'm using the America/New York timezone. In the Fall we "fall back" an hour -- effectively "gaining" one hour at 2am. At the transition point the following happens:

I have some strings like this: 2012-02-05T07:42:47.000Z mixed with other strings. It is always in this format. (but the numbers are not the same, of course...the times are different) (not Sun, 05 Feb 2012 07:42:47 GMT ) I want to know whether a string matches that format. How can I determine that? It's so complicated with the colons and dots and stuff.