I currently have my exterior lights (1 on each side of garage door) and front entrance light on a dimmer control, but would also like to be able to put them on a timer to come on say at a specific time and turn off at a specific time.
Is that possible and if so, what do I need to be able to do both functions (dimmer and timer)

Most combonation ones Im seeing are only going to last about 60 minutes. Im not sure how long you want to run the lights for. The other way to do it is to put the timer circuit first to feed a dimmer switch to the lights. That way the timer always has full power and should keep time accurately.


Ref

Buy a Lutron Maestro® 300 Watt Single Pole Dimmer and Timer Switch, White - MA-L3T251-WH at The Home Depot

Ref, thanks for your response to my question. Yes I did see this particular switch but this would not be a fit with the 60 minute time. I was thinking of 4 hours or longer as a time on and then off.

Can you help further with more detail of the suggestion that you made regarding the timer circuit first. I am a novice and have limited knowledge on electrical issues. I would have an electrician complete any installation, but just trying to determine what or how it could be done.

Here is a timer that could work for you, many times, these types don't have a neutral and work because of a load in place, a dimmer in series with these should still work.
Intermatic EJ500C 24-Hour Electronic In-Wall Timer

Stratmando, thanks for your response. Yes this would probably be a fit for the time requirements. The next issue would then be how to incorporate the dimmer since I only have the single switch box to fit both timer and dimmer.
When you refer to dimmer in series, are you speaking about dimmer in a gang box beside the gang box for the timer and wired in series?

Yes, but it takes 2 spaces. Will see if I can find a combo later.
If the wiring goes through the electrical panel, dimmer could go there.