It's easy to change the date format in Microsoft Excel. You just need to use the "Date" drop-down menu, which gives you plenty of options.

How to Auto-Format the Date in MS Excel. When you create Microsoft Excel spreadsheets that contain one or more columns of dates, you can make things a bit easier if you pre-format your cells to ...

Excel has a surprising limitation that you may not discover until you try to enter more than 15 digits in a cell. The application can only store numbers with15 digits of precision.