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

You can change the date format in Google Sheets and customize the appearance of calendar dates in a spreadsheet.

Like Microsoft Excel, you can change the formatting of date and time in Google Sheets as well. For that, select the cell where the date/time is visible, go to Format > Number, and select ...

Google Sheets and Excel have a lot in common, date sorting isn't among them. Here's how to use Google Sheet's somewhat confusing sort by date feature.