How to clear the selected value

[purandharangular]

Hi I would like to know how to clear the selected date from component.

I have a requirement as follows:
Date 1 must be always selected first followed by Date2.
if user chooses Date2 first then Date 1....
at the time of value changed of Date1 I should clear Date2 to force user to select Date2 again...

hope this is clear

thanks in advance