I have a spreadsheet in which I am trying to count the number of tickets opened in a given time range. The column data goes from C2:C530 and it includes time data in the form of HH:MM

S AM/PM. The first thing I did was changed this to 24 HR format HH:MM. I tried the following countif statement and keep getting zero returned for the result.. can someone please show me where I am going wrong with this?
COUNTIF(C2:C530,">=00:00 AND <=00:59) I tried removing the
quotes but excel didn't
like that too well.
Any help would be appreciated.