Before I answered this thread for the first time, I kind of wondered why OP was asking this question. To me, a timer is just a standard equipment. I have printed without one in the past, it still is something that belongs in a/my darkroom.

I wonder if OP have some darkroom experience already or if he/she is just setting one up and evaluating his/her options? Or, is this a question of more advanced timer and if he/she is wondering it is a better idea??

Would someone PLEASE invent a genderless pronoun?