I have never kept a watch "sealed" over the night but always open it on the same day I receive it.
Still it's nice to get older watches in their original packing and unopened. Normally I take such watches to a watchmaker of the brand and ask him to study if the watch needs service. If yes, I'll get the watch serviced before I start wearing it. My 5450P is waiting for such inspection as well as new strap. However, thanks to the advance technology, it's quite unlikely that this watch would be short of oil.
Best, Kari
