The counting of milliseconds between two specified dates helps us to find the number of hours, days, months, etc. by doing easy calculations.
It contains a single parameter string that represents a date. This method returns a number that represents the number of milliseconds.
Let's see some illustrations of using the parse() method. In the first example, we are passing the valid date value, and in the second example, we are passing the invalid date value to see the result.
Calculate the number of years between January 1, 1970 to March 21, 2012: