If you mean how long it takes to get an egg, it really depends on how what pokemon the female (or non ditto) is and how they like one another. It's based on steps, not time, so keep walking and comng back. As you could expect, it takes longer if your pokemon do not like one another much than if they get along. It takes a minimum of 250 steps for an egg to appear in the day care.
As for hatching, it varries by pokemon type. Two frequent hatching number of steps are 4080 and 5355. Most baby pokemon hatch at 2850. Good luck!