When is the best time to take anti depressants like venlafaxine?

Maybe. Best to take it with food at about the same time every day. Keep track of your mood changes so you can report to your doctor whether or not it is changing. Watch also for any side effects.
Depends. Different individuals respond to ssri's, like venlafaxine, differently. Generally, venlafaxine makes people a little more energized, and so they should take the medication in the morning. However, sometimes it can make the person sleepy, so it is then best to take it at night. I recommend to try it in the morning when not driving and see how it affects you.