how long does it take for a male eevee and ditto to lay an egg

From Pokemon Breeding Guide

Pokemon Compatibility:
This is the sticky mess of Pokemon breeding. Some Pokemon can mate with others, others cannot. That is all determined by Egg group what species can mate with another. The second part of mating is just how long one would have to wait to find an Egg. This section details the compatibility and what each message from the Daycare Man means.

“The two prefer to play with other Pokemon than each other”
These Pokemon are NOT COMPATIBLE. It could be one or both of the parents cannot breed, they could be from different egg groups, be a genderless Pokemon (which can only breed with Ditto), they could be the same gender.

“The two don’t seem to like each other much”
The Pokemon are COMPATIBLE, but are different species and have the same Trainer IDs. Expect them to take a long time to breed.

“The two seem to get along”
The Pokemon are COMPATIBLE. The two Pokemon are the same species (and evolutionary level) and have the same Trainer ID or they are different Pokemon with different Trainer IDs. Will breed faster.

“The two seem to get along very well”
The Pokemon are COMPATIBLE. The pair of Pokemon are the same species (and evolutionary level) with different Trainer IDs. Will breed the fastest.