Learned the hard way that pouring concrete at 2pm in July is a fool's game
Was finishing a 12x20 slab in Tulsa last summer and started the pour at 2pm because the homeowner wanted it done that day. The mix started setting up on me within 20 minutes, way faster than the 45 I planned for, and I was scrambling with a magnesium float while the surface was already crusting over. Ended up with a rough patch near the south edge that I had to grind down and patch the next morning, cost me 3 extra hours and a ticked off customer. Now I won't touch a pour past 10am in summer no matter who's asking, anyone else got a hard cutoff time they stick to?