Converting data that is showing as "General" to a custom "Time" format

[scarames]

I have many pages of a spreadsheet that has five different columns of time, all generated in "General" data format. I need these to read as time, i.e., 4:40 am (not military time). I'd like to be able to do this without just retyping once I've formatted the column. Does anyone know how, or is there a way? Reason I say custom is that I usually choose custom and leave off the m from am/pm. Thanks. Excel 2007

[ChemistB]

What does the data currently look like? If you're seeing "General" after a time is inputted, then odds are, Excel is seeing it as text. Can you upload a spreadsheet showing what you have currently? (Go Advanced> Manage Attachments)

[scarames]

Here's a quick spreadsheet showing what I've got. What happens is that I use this as a master and have to sort it by times for various other forms I copy it to. Showing when buses leave the depot and how much time the drivers actually work. Thanks so much.