does orientation of moon takes 3 days to complete its circle?

Question

does moon realy takes so long to complete its rotation round the earth in such a way that muslims celebrate eid at one part of the world on one and the other part of the world after 3 days.can appearence of moon be calculated by scientific calculations to fix a date of eid for a certain parts of world .a little earlier to remove the confusion

Answer 1

it is based on the appearance of the cresent to the naked eye, not telescopes.