If you are doing a drop in visit for 2 dogs in the same house do you stay an hour? 30 min for each? Or just 30 minutes total for both?

I have just done 30 min for both before, but feeding instructions from the owner are 30 minutes apart. For example for 1 dog he has feeding time at 7:00 am. For dog 2 he has feed time as 7:30 am. I went ahead and stayed 50 minutes this morning but think I over stayed ; ) He has never used Rover.