Technically, zero; "incubation" is literally the period when an animal sits on its eggs, which toads do not do.
about a week
A storm dragon has an incubation time of 3 hours.
The frostfire dragon has an incubation time of 12 hours.
The effect of decreasing incubation time on optical density is that optical density decreases. Incubation time and optical density have a proportional relationship.
The incubation time for a rainbow dragon in DragonVale is 48 hours.
The incubation time for the Swamp Dragon is 9 hours! ~DragonVale Support Team
The incubation period of tonsillitis the time between when you get the infection until it breaks out. The incubation period can last from two up to seven days.
Incubation period
the answer is 7 weeks
http://www.birdingguide.com/bird_families/pigeons.htm
24 hours
20 years