Roflcopter that's not true for all. Some items that say 30 days are only 30 days, but the weapons +8 and +16 don't say 30 days, those are permanent. Each one has its own description.
Already here, Baium rewards for a chance to get a reward. Possible +8 or +16 weapon ready for you to try along with other goodies as well. Low chance probably but still up in the store.