Convert Time to hour and mins

Hello again. It's me again.

Can you give a formula on how I convert the first time interval. I attached the sample file.
Note: only the first time interval not the second one.

Result should be like this:

Hour Convert - Minutes Convert
12:00 - 30:00
15:00 - 00:00
10:00 - 00:00
8:00 - 00:00

and so on.


THANK YOU in advance.