Originally Posted by
Shanqx
there is no restriction on stopover, technically you can stay as long as you want, but you have to book your entire trip back to your origin by the time you request. Given that airlines don't release seats too far in advance (11 months?), your stopover per destination can't be longer than that initially, but you can always change your trip later for a fee, I believe it's $90 per change and SEs have 1 free change.
All travel must be completed within 12 months of that date of issue of the ticket. So long as you keep within that, stay as long as you like.