Yes, you do. 0000 is military time format, not just 24h clock. 12h clock adds AM/PM. 24:00 and 00:00 are identical and more personal choice than anything.
Plenty of weirdly shaped time zones, though. And Spain in the CET doesn't really make sense, they're to far west. But businesses are all "keeping track of time is soooooo hard"... weird how they don't seem to have much problems in international trade...