Excel stores dates as numbers. 1 is 1st-Jan-1900.
You can use formatting to display a date any way you want to.
The date 29-Jan-2018 is the number 43129, so when you format the cell as "General" it will show that number.
You can select a different format, for example "Short Date" or "Long Date", which will show the date following the conventions of the regional settings of your computer.
Or you can format the cell with a custom format and use any format you like by specifying a format string. Some format string examples are
dd-mm-yyyy ' this will show as 29-01-2018
dd/mmm/yyyy ' this will show as 29/Jan/2018
Note that the format does NOT change the value of the cell, just how the cell is displayed.
Let me know if that helps or if you need more info.