Time really isn't to big of a factor as to how long the blade will last. Uses is more of factor. For example if its a new blade it could be find for years. If you have used it a couple times and typically only get a three uses out of the blade and leave it for a week or two it my or my not work well for you.

The other main factor is storage condition. Was it wet when you put it away this will speed up degradation of the edge. Is it in the bathroom with a shower.

These are more of the factors to look at