Given a date , returns number of days elapsed from the beginning of the current year ( 1 st jan ) .
function offsetDays ( d , m , y ) { var offset = d ; if ( m - 1 == 11 ) offset += 335 ; if ( m - 1 == 10 ) offset += 304 ; if ( m - 1 == 9 ) offset += 273 ; if ( m - 1 == 8 ) offset += 243 ; if ( m - 1 == 7 ) offset += 212 ; if ( m - 1 == 6 ) offset += 181 ; if ( m - 1 == 5 ) offset += 151 ; if ( m - 1 == 4 ) offset += 120 ; if ( m - 1 == 3 ) offset += 90 ; if ( m - 1 == 2 ) offset += 59 ; if ( m - 1 == 1 ) offset += 31 ; if ( isLeap ( y ) && m > 2 ) offset += 1 ; return offset ; }