How long does it take for bobwhites to hatch

I am incubating bobwhites I bought and had shipped to me and I have heard it takes 22-23 days for them to hatch and it is day 23. I checked one of the eggs which I know isn't recommended but when I checked it hadn't pipped into its air cell yet so I didn't know if it was common for eggs to hatch on the 24 day or not. I have sixty of them so I assumed at least one would of hatched by now. I have hatched about four rounds buttons and every time they hatched a day late so I wasn't sure if I should expect that or not. Thanks

 

Well I'm posting an update and all the worry and wondering was for nothing I haven't looked for very long but I saw that two of my eggs have pipped and I was lucky to see them since the spots seemed almost microscopic.