updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -214,6 +214,8 @@
  * [ValidateEmail](https://github.com/TheAlgorithms/Javascript/blob/master/String/ValidateEmail.test.js)
 
 ## Timing-Functions
+ * [GetMonthDays](https://github.com/TheAlgorithms/Javascript/blob/master/Timing-Functions/GetMonthDays.js)
+ * [GetMonthDays](https://github.com/TheAlgorithms/Javascript/blob/master/Timing-Functions/GetMonthDays.test.js)
  * [IntervalTimer](https://github.com/TheAlgorithms/Javascript/blob/master/Timing-Functions/IntervalTimer.js)
 
 ## Trees