Upgrading from 1600ton mate to master

I’ll be testing for my 1600ton mates license in about a month. I am currently an AB on harbor tug. Once I have my license and TOAR, I have a spot on a tug over 100ton. However, I will only get to run as mate when captain is over his time. The rest of the time will still be running as AB. Will I be gaining time towards upgrading to my masters by simply holding the mates license or only when I actually get to run as mate?

If you are on the logbook as a mate and the company records, and they write your seatime letter as such, then yes

You need time as mate. If you’re serving as AB, it doesn’t count.

That’s what I figured thanks