What does "T" and "Z" mean

Question

I need information about this date '2015-05-12T00: 00: 00Z'. What does this mean “T” and “Z”? Can anybody help me? I don’t know how they understand it. I need to convert this data to another format

Answer 1

T is just a marker in which time begins.

Z is the Zulu time zone, which is the same as UTC.

From the Wikipedia article on ISO 8601

A single point in time can be represented by concatenating the full date expression, the letter T as a separator, and the actual time expression. For example, "2007-04-05T14: 30".

[...]

If the time is in UTC, add Z immediately after the time without a space. Z is the zone designation for the UTC zero offset. “09:30 UTC” is therefore represented as “09: 30Z” or “0930Z”. “14:45:15 UTC” will be “14: 45: 15Z” or “144515Z”.