wrong count 1 more month is added

[AldoFerrari]

Hello ;-) I am counting down from today (20 february 2024) till 14 september 2024 at 11:00 but the result it is:
7 MONTHS, 22 DAYS, 11 HOURS, 10 MINUTES

but the correct one should be:
6 MONTHS, 22 DAYS, 11 HOURS, 10 MINUTES

countdown( new Date(2024, 9, 14, 11), function(ts) { document.getElementById('days').innerHTML = ts.toString(); }, countdown.YEARS|countdown.MONTHS|countdown.DAYS|countdown.HOURS|countdown.MINUTES|countdown.SECONDS);

even changing to days:
countdown.DAYS|countdown.HOURS|countdown.MINUTES|countdown.SECONDS it give back
236 DAYS, 11 HOURS, 6 MINUTES
instead of
206 DAYS, 11 HOURS, 6 MINUTES