repeating cycle timer information needed please

would appreciate anyones input on this
i want a timer that will enable me to switch my lights 6hrs on 12hrs off continually in effect giving me an 18 hour day
the only one i can find is a solatel pro timer at 270 us and then post on top cost rises to almost 400 us
i am only a retired hobby grower for me and the wifey so i cannot in any way afford or justify the purchase
but i would love one or something similar
does anyone know of anything else that would do the same thing or even if someone has made thier own that i could build
thanks for reading this
hopefully you guys can help
thanks

Don't understand the schedule. For Vegging 18 hr's on 6 hr's off. Flowering 12hr's on 12hr's off

Besides the whole why the hell would you want to do that question..

You could probably program that schedule into one of the digital seven day timers

But anyways...why ?