Er .. yes ... that is exactly what you would expect!
12-hour clock starts at 12:00 am (midnight) and goes to 12:01 am, 12:02 am ... 12:59 am, 1:00 am .... 11:58 am, 11:59 am, 12:00 pm (midday), 12:01 pm ... 12:59 pm, 1:00 pm, 1:01 pm ... 11:58 pm, 11:59 pm, 12:00 am (midnight).
24 hour clock starts at 00:00 (midnight at start of day), and then goes to 00:01, 00:02 ... sand so on in an ever-increasing sequence until 23:58, 23:59, pausing instantaneously at 24:00 (midnight at end of day), which is equivalent to 00:00.
Hope this helps!
Thanks Julianh. I feel so stupid.