In this case I don't see a gain in making a class out of 1 function. You would gain more if for example you have a class for weeks and there are different actions that a developer can make that class have. For example a developer can make a week to be print out in different formats, to be added or substracted. Stuff like that.

I am not sure if I explained myself well, but there are various reasons to design classes and one of them is to encapsulate common actions (methods) applied to an object.