Storing hour and minute value in letegral form
hh = ( str [ 0 ] . charCodeAt ( ) - 48 ) * 10 + ( str [ 1 ] . charCodeAt ( ) - 48 ) ; mm = ( str [ 3 ] . charCodeAt ( ) - 48 ) * 10 + ( str [ 4 ] . charCodeAt ( ) - 48 ) ; let requiredTime = 0 ;