I am trying to add up time duration values, given to me, in the following
format

hh:mm.

The hours (h) value always resets to 0 when it reaches 12:00.

I need to calculate the total number of hours used. For example:

5:37 Five hours and thirty seven minutes.
13.58 Thirteen hours and fifty eight minutes.
25:14 Twenty five hours and fourteen minutes.
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44:49 Forty four hours and forty nine minutes.

How can I do this?