7 months
Exclusively, five months
January follows September by 4 months. There are three intervening months: October, November and December.
3 (excluding May and September) - the summer months of June, July and August.
4 months (June, July, August, September)
Including the start and end month in the calculation, there are seven months between the two months.
There are 5 months between June and December. July, August, September, October and November.
Between the months of August and February fall the months of September, October, November, December, and January, which adds up to five months.
6 months fall between February and September: March, April, May, June, July and August. That time span is half of a year.
8 months
September and November are separated by October.The following year's September is the 10th month after a given November.
It is just over 6 months. It is exactly 27 weeks.