Current expiration timeout is 24 hours.

If you stop staking for 24 hours, you will have to start again. It is a hassle if your internet connection is disrupted for 24 hours or if you forget to restart staking if your wallet is closed or you must reboot the computer.

It was a community requested change and is a good one.

Also, if you stake for 1 year without timeout, the update will allow you to reach up to 5% instead of the current maximum interest.