Day 60 is pretty average if you incubate at around 88-89F. They can sometimes take a little longer than 60 days to pip.
You can wait until one of them starts trying to cut out of the egg before you cut into it. If you do want to give the little ones a chance and see how they do, either just wait for that first little pip in one egg or cut on day 60.
You could also just wait and see what happens... but after day 68 if they haven't cut themselves out, they probably won't.