I am surprised more people have not reviewed this terrific time difference app. This app makes it incredibly easy to figure out the difference between years, months, weeks/weekends, dates, hours and seconds. The other feature is the ability to add or subtract to the same. You have the option of using a 365 day calendar or a Monday through Friday business calendar. Results can be shown in 24 hour military time or 12 hour am/pm timeThe results are shown on the same screen as the calculation and, one of my favorite features, you can export those results to a file or share them by text, email etc. The developer also included a native iPad version, which looks great on my iPad 11 inch. AND, it is completely free with no ads**👍.