Honestly it depends on how you learn. Not everyone needs a massive amount of time to study. I come from a situation similar to yours–I'm working full-time and studying. Ok, I don't have a ton of other things on my plate like kids or grad classes, but that doesn't mean after a long day of work I'm looking forward to having just enough time to eat dinner and then get consumed by studying.
You are fortunate in that AUD is a relatively easy area–having just finished A5, I can promise you that *most* of the lectures go by fast and the key to doing well with the material is mostly memorization. It's an area where you don't necessarily have to understand the topics inside out as long as you can regurgitate information.
I've found that since my full-time job began (I started a position with my firm at the end of August) I've obviously been studying less than I did for FAR during the summer because there's only so much a person can take. Studying is important and needs to get done, but don't throw your life away. You still need to take care of your mind and body–stay physically active and TAKE A NIGHT OFF!
This might all have to change when you start studying for FAR as it is a much harder exam, but when it comes to AUD….relax. If you tackle one chapter a week (lecture Monday, review notecards Tuesday, HW Weds/Thurs, Friday off, quizzes/supplemental questions Saturday, and progress test/simulations Sunday) you should feel pretty confident in the material without killing yourself and sacrificing every living second of your time.
Hopefully I don't have to eat my words after I take AUD next month, but good luck either way!
FAR 07/27/11 - 87
AUD 10/01/11 - 85
BEC 11/15/11 - 87
REG 01/03/12 - 92
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