Lighting Timer

Hi all I'm new to keeping fish and I've reading about keeping the lights on for various amounts of time. Some people say 7-8 hours others 10-12 hours all kinds of times really so I've decided I will probably get an idea myself by just letting it happen and using my head as to what works bests for my tank. Anyway question is i leave for work at 5 am and I cans be back anywhere between 4 PM and 10pm so the period I leave them on for could vary from day to day, I'm looking to get a timer so start off my giving it 10 hours a day does anyone have a timer they recommend or is any as good as the other. Also your ideas on how long to leave them on for will be greatly appreciated.

Thanks

i use a plain old basic one aswell  , my main lights are on from 9,30 am till 8,30 pm but thanks to my complicated light system during this period of day light i have 6 cloud cycles during the day of which i have programed to varied amount of times and then it also includes a night light which follows a lunar cycle from full to no moon  , i think when it comes to lighting its a bit of trial and error to find something that works for you and your tank start somewere between 8 -10 hours and adjust to suit

Thanks for the help, I will start of at about 10 hours then and see how it goes from there.  Trip to b and q then for me as I want the air pump to switch off during the night as it's in my room!

I got a cheapy air-pump off Amazon and it was sooooo noisy. I opened it up and bent the arm with the magnet on a few mm further away from the elctro-magnet..... and now the bubble bursting on the water surface are noisier than the pump. However - this may not work on other pumps, but quietening them down is possible.