Each distribution can be reffered as an Epoch that lasts 7 days. New epoch starts every Thursday at 00:00 UTC.
User needs to remain locked for the whole epoch until rewards can be claimed for it at the start of next one.
Example, if user locks within Epoch 1, rewards will be available at the start of Epoch 3 for Epoch 2.
Rewards are accruing only for fully locked epochs. Lock time spent within Epoch 1, would not yield tokens.