How long does it take to breed

How long does it take to breed pokemon.

That depends on which pokemon you left at the daycare. The man outside the Daycare has some lines which indicates how long it takes.
For example: "The two seem to get along very well". This line means it doesn't take that long to get an egg (ride your bike for 1-2 minutes or something)

It can also say: "The two don't seem to like each other". This means it will take about the double of the previous line to get an egg.

And if he says: "They prefer to play with other pokemon". Then you won't be able to receive an egg from the 2 pokemon you left at the daycare

What stuiterbal said is completely correct but there is one thing missing: it's not time you need to breed an egg or even to hatch the egg. Its steps in game, you need to go around or just go up and down/left and right and then check the oldman for an egg or if you are trying to hatch, a message will pop up.