You can change the date & time format in Google Sheets & Excel Online using this guide. Use different date & time formats in spreadsheets.

If Microsoft Excel does not recognize dates, then there is something wrong with the formatting. Use any of the methods mentioned here to format cells perfectly.

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.

The ramifications of missing a due date can range from simply adjusting the date to getting fired. Don't take chances with deadlines when a simple conditional format can remind you.