I should add this is regarding solo, but should also apply if I'm in a pool as well.
Saving is not needed when you mine solo.
Imagine this as buying lottery tickets in a shop. There is no difference if you continue buying for 10 hours without stops or do this for 5 hours, then leave the shop and come back next day for another 5 hours.
For instance, say I'm 3 days in. If I stop, do I lose those 3 days I've been working at and start all over or do I just pick up off from the 3 days?
Those first 3 days are ALREADY lost because you didn't find anything, so you can't lost them again.
When mining in slush's pool you can lose about 20-40 mins of work if you disconnect in the middle of a round.
In other pools you won't lose anything except for the one share that wasn't sent by you yet.