Select the cells you want to format
Right-click the selection
Click Format Cells
Go to the Number tab
Select Date
Choose a date format from the list
Click OK
To use a custom format, select Custom
Enter a date format code such as dd/mm/yyyy or mm/dd/yyyy
Click OK
You can also use the Home tab
Open the Number Format drop-down
Choose Short Date or Long Date
For more options, click More Number Formats
If Excel is not recognizing the value as a date, convert the text to a date first