Studying back-to-back without breaks (aka "cramming") will not increase your progress on Cerego, as it has shown to have very little impact on long-term memory retention. The best time to study is when our system identifies facets as needing review, as this is when it will have the greatest effect on your memory.
We recognize that it's not feasible to study exactly according to the schedule, and it's alright to study a bit before or after the specific deadline. However, if you study much too early, you will see only small increases in progress on correctly answered items. On incorrectly answered items, you will see substantial decreases in progress. On the other side, if you study infrequently, you will have low retention and will not be able to remember portions of the material.
Staying as close as possible to the schedule will have the greatest memory benefit as you go through your studies, and will also have the greatest effect on increasing your progress.