Homekit Automation "Turn off" time longer than 4 hours

I have a few aquariums with automated equipment. The lights and CO2 injection are on timers. One of the tanks needs the lights on for 12 hours, another for 8 hours, another for 10. The CO2 needs to be on for 7 hours. It's a massive clutter in my automations to have separate "On" and "Off" automations for each of these many things.

I also have some lights I turn on at sunset that I want left on for more than 4 hours (sun goes down at 4:30pm here in the winter). The 4 hour limit in the automations seems arbitrary, and for almost everything I use it for, far too short.

PLEASE change this so we can pick a specific time. The rolling scroller is cool (I guess), but picking a specific time is FAR more useful.

(If anyone out there knows a way to make this work *other than* creating separate automations for "on" and "off", feel free to clue me in...)