My legion is trying to increase our base combat coordination by setting up a regular schedule to show up for. Unfortunately, because the timer is set to 8 hours, and because we're trying to maximize our opportunities for base combat by doing 3 per day, our show-up times are constantly slipping by 5-10 minutes.

Would it be possible to set the timer to 7-7.5 hours so we don't slip backward?

if the timer is falling behind (due to the time to scan and discuss and lock) you can move the timer ahead by having another legion share their lock with you the moment your timer hits 0... if you lock in on a shared base, what remains on their timer will also be your timer, thus moving the time ahead the amount of time they have already spent locked onto that base.

it won't matter if it gets moved ahead too much either, because you can then freely adjust when you start the next base... in this manner you wouldn't have to miss a whole base combat session just to fix the timer