How i fix this Array [ ]

Question

Array index [3] = month 5 - array index[2]
https://code.sololearn.com/W5G1lcrs4uv0/?ref=app

Answer 1

Lots of useful links on SO: https://stackoverflow.com/questions/1296358/subtract-days-from-a-date-in-javascript

Answer 2

Date(...then).now() - Date().now()
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Date
Date.now() method
Returns the numeric value corresponding to the current time - the number of milliseconds elapsed since January 1, 1970 00:00:00 UTC, with leap seconds ignored..
The returned is in milli second, multiple by 1000 if you need

Answer 3

Can you remove your earlier question which does not have a code attempt?
https://www.sololearn.com/Discuss/1779937/?ref=app