this is a little late but..
if your AC remotes have a display on them (that shows the temperature, fan speed, and such)
take a look at Tado, its like nest for smaller ACs
it's a small white box (looks like a thick drink coaster) with an IR blaster.
you can set up as many schedules during the day as you need.
the app has location services, so if no-one is home, it will set the AC to away mode (you set how you want, mine is just a high temp as velocityg4 suggested, and because of the cat)
and the new version is homekit compatable. so you can have Siri set the temp, instead of just on and off
They also work with ifttt.com, so you can automate that way too.
I have a couple that are button presses in my widget screen, one turns on the ac on as I leave work, or another that keeps away mode from kicking in if I'm not leaving the house that long.
Sensibo makes basically the same item (no homekit though)
since I have an older Tado model without homekit, I use a program called homebridge, It makes non-homekit things work with homekit, and there are a ton of plugins so you can add control for pretty much anything controllable over the net. there are plugins for both Tado and sensibo.