Question about whether posting at 6am really does anything for reach

I help run a small page for a hardware store in Boise and figured the whole "post early" thing was nonsense, just something people repeat online with nothing behind it. For about 5 weeks I posted everything around 8 or 9 at night, right before I locked up, and our stuff averaged maybe 40 or 50 likes and a couple shares. Then in late January I started scheduling the same kind of post, same photos, same captions, for 6:15 in the morning before I opened. The reach number in the app went from around 900 to almost 4,100 on one post about a snow shovel deal. Not a fluke either, the next two hit 2,800 and 3,300. My guess is our people are contractors and trades folks who scroll with coffee before they head out, not at night when they are wiped. The catch is you have to actually be awake to reply to comments in that first hour, and I am not a morning person at all. Has anyone tested this for a local business and found the sweet spot was somewhere in between, like 7 or 8, or did early really win out over everything else you tried?