Actually that is an automatic timer with a light sensor and from the settings is great for your vegging cycle but has no 12/12 setting the dusk to dawn setting will activate the light sensor and it will stay on permanently unless you trun on a light then it will turn off not good for flowering
The best type is a conductive/resistive type because the different types of draw on the circut. they are relatively cheap and mine was an outdoor light type and was under 10 U.S.