quick question for baby's easter present

nikeman

I have a 7 1/2 month old and we got her a little swing for easter. My original plan was to hang a board between 2 trees but at the last minute everyone started hating on that idea so I was forced to try and get the grass mowed and set 2 4x4s in the ground in a 2 hour time frame before dark after work. I got as far as digging the holes but then it was dark and time to go pick up my baby so I could feed her and put her to bed... Anyway, I have set both posts and finished filling the last hole with concrete around 9 this morning. I saw somewhere that after 5 hours concrete and hold a certain amount of PSI but I am not sure where I read that. How long until this stuff can hold my baby while swinging? I would like her to enjoy the swing today but of course I would much rather not see her fall on the ground because the concrete wasn't dry enough... I buried each 4x4 about 2.5-3' deep in a hole close to 7" in diameter (wanted to make it 8" diameter but I managed to find 2 spots with big roots just perfectly in the way) I think I probably dug a hole down through roots that are coiled into a circle or something crazy like that! lol