Timelog - minutes

Timelog - minutes

Regarding timelog: "HH:MM"
I manually enter time. Is the "MM" 0-59 minutes? For example, if I spend 2 hours 20 minutes is it as simple as entering "2:20" or do I need to do some formula?
This must be obvious to everyone as I didn't see this question in the forum. 
Thank yoU!