15,552,000 with only months with 30 days2592000 * 6 = 1555200060 seconds in a minute. 60 minutes in an hour = 3,600 seconds in an hour 24 hours in a day = 86,400 seconds in a day February has 28...
24105600
.
It really depends on which 9 months you are talking about.
A month can have anywhere from 28 to 31 days. Different months will have different numbers of seconds.