Windows Calculator and The Guardian apps have just picked up new updates in Windows 10. While the Guardian(which has come out of beta) update seems to revolve around bug gixes and optimizations, the Calculator update adds a feature that will most likely be a life-saver.
In this new version of the calculator app (10.1511.60020.0 for anyone interested), there is now a date calculation feature that allows you to calculate the period between two dates. Its a small feature, but one that will be quite useful in practice to a vast majority of users.
Download the apps from the store links below.