converting time units

I am attempting to convert time units from one format to another. Here is an example of what I am trying to do (but without success).

Currently I have time in the following format (hh:mm:ss)
I need to have this format converted to just minutes (mm)

I have tried =convert(A1 ("hr":"mn":"sec","mn")) and I receive an error saying the formula is invalid.

I don't know of any other formulas to try.

In other words I need 9:46:55 (9 hours 46 minutes 55 seconds) to say 586.92 (586.92 minutes)


Any advise is greatly appreciated. I've been pulling my hair out on this one for a while now.