Your coins will mature anyway, wallet open or closed, so you'll stake.
You'll just get less stakes if you don't run it 24/7.

•   Coin (input) is eligible to stake 3 days after the transaction that put it in your wallet.
•   Every second it gets a better and better chance to mint as it gets older.
•   But at 9 days after sitting in your wallet, the chances get no better.
•   Every second your coin will earn more and more interest once it mints.
•   But at 15 days, the potential earnings are capped. That means you can't open your wallet after 365 days and earn 20% interest. The most interest you will earn on an input is 0.822% (20% * 15 / 365).

•   So if you open your wallet every six months to stake, you'll earn just over 1.65% interest (1.00822 * 1.00822).
•   If you open it every 3 months you'll earn about 3.3% interest.
•   If you open it every 45 days, you'll earn about 6.7% interest.
•   If you open it every 22.5 days, you'll earn about 14% interest.
•   More frequently than that, you'll approach compounding to nearly 22% (based on a nominal APR of 20%).

The last calculation goes like this:
(1 + (0.20 * 3 / 365.0))**(365.0/3) - 1