In most NLEs timecode entry (e.g. to go to a time in the editor) does NOT require the colons entering, or all the numbers.
Typically an entry of 12 would take you to the nearest HH:MM:SS:12
Period acts as :00, so 12 period period would go to nearest HH:12:00:00
10 period period 15 would go to 10:00:00:15
Frames entered above the current frame rate are calculated so 35 would go to nearest HH:MM:01:10 in a 25fps project.
+ and - allow relative movement.
PPro is only recently getting to grips with this though.