format column C to hh:mm (so no AM/PM is shown)
In C1 enter
=if(b10.5,b1-0.5,b1)
this will then only show the 12h clock even if PM
in D1 enter
=if(b10.5,"PM"."AM")
Then if you like hide column B
Copy/fill the formulas in C1 and D1 down as needed

Regards
Steve

"cuartetto" wrote:

In column B I have 1000 time entries with the following format. 9:30AM,
10:30PM. I would like to move the AM or Pm into a new column. I've tried
"fixed width", also tried changing the format to put a space between the time
and the AM/PM, but nothing has worked.

Any suggestions?
Don