Proof-of-Stake rewards the users that want to use the coin as an investment and earn interest by making them hold their coin (min. coin age: 30 days, max. coin age: 90 days) in the wallet and participate to the network (while staking) for a minimum amount of time before earning the rewards.
In order to stake you must meet 3 conditions:
–have some coins in your wallet that are at least 30 days old.
–have your wallet encrypted.
–have your wallet unlocked.
Your wallet doesn’t have to stay online for 30 days to earn the rewards.
But once your coins are mature and you want to start staking, you have to leave your wallet online and unlocked for a few hours before earning the rewards.