KMS CS item that extends equip expiration

I am not sure if I explained it well enough. You may only have the expiration date be 30 days after the current date. However, if you do keep pumping NX into the game, you can extend the item indefinitely. The annoying part is that you can't do like 3 20 day hourglasses at once to get 60 days, but that you have to wait until enough days have passed to use the next one.

Ohh, yeah that's not how I read it. So you literally have to wait for all 30 days to pass before you can use a new hourglass?