It would probably be better overall...

If you want to pick one time of day I'd say Morning...This give the body the most amount of time for the body to metabolize the juice before going to bed.

Alternatively, It can be beneficial to juice the apprpriate colour Fruit/Veggie for a particular time you are free.
Lookup the "Rainbow Diet" by Gabriel Cousens - at least to know about which foods for which time of day.
This idea is used in Germany to curb diabetes for example.... Tweet