Most folks are not aware of half of the things you can do using your Calculator in Windows. Below is but one of the cool uses.
For planning anything date related, the date calculation function is great. It allows you to calculate the difference between two different dates. For instance if you were born on August 17, 1957, this function will calculate and tell you that on August 17, 2016 you were 21,559 days old! I am not sure that information would be very valuable to you, but there are many other uses for this function, such as wedding invitations, vacations, etc.
This function will also allow you to add or subtract days from a specific date. Say you have a 4 month deadline – this tool will allow you to figure out what that date will be. Warranties – you can figure out how many days are left!
I am certain you will find lots of uses for this!