[cphajduk]

How long?

Consecutive stay in the ISS has been completed for 355 days (almost year) with less than 10 people onboard at that time.

[m4rtink]

Cumulative perperson record is currently 878 days, longest single flight personal record is 437 days. For more see:

https://en.wikipedia.org/wiki/List_of_spaceflight_records#Mo...