How do i make a timer for..?

[AlexPan]

Hey every one. I'm making an incubator for the Stick/Leaf Bug's eggs, and wanted to poot in a small fan to make sure there will not be any hot spots.
Any one know how can i do and what do i need to make.., a fan turn on say every 4 hours for 5 minutes at a time? Any tips will be great! Thanks.

[gonesnakee]

Timers are available for purchase at all places that sell electornic supplies etc. Can also be purchased at places that sell hydo supplies etc. Try Revy, Home Depo, Radio Shacks etc etc etc Mark

[Auskan]

Or Walmart.