JFK is mostly 3 day (2 leg) trips, although the fall and winter schedule has more 4 day trips (also two legs).
We have a daily 7 day Moscow/Atlanta/Moscow trip (this is a six day trip in summer), as well as daily 6 day Paris/ Cincinnati/ Paris and Frankfurt/ Cincy/ Frankfurt trips. (All are 4 legs, with 3 layovers.) A 6 day Rome/ Cincy/ Rome may come back to NYC next year.
Next year we will also get a Dakar/ Nairobi/ Dakar 6(?) day, and possibly a Dakar/ Capetown/ Dakar 6 day.
We only have one S.A. trip for now: a 4 day Sao Paulo trip with 2 legs and a 36 hour layover.