This is a common hack with business travel where prices of flights including a Saturday stay are much cheaper (aimed at holidaymakers) than weekday flights (business travel). If you know you will need to travel to XYZ every second week M-F for two months then you buy one two month return SFO-XYZ-SFO and then buy the rest of the flights as 11 day flights back from XYZ Friday to the Monday of the following week (XYZ-SFO-XYZ)
All the tickets include "weekend stays" but you never spend a weekend in XYZ.
The OP may have used a one way ticket or something for the original trip since airlines don't book more than a year out.
Used to do this. Weekly round trip tickets from CA to the US and a longer round trip ticket the other direction surrounding them (or 2 one ways? Don't remember) The airline (Air Canada) got really mad at me and claimed there was a T&C violation. Wasn't my idea but the travel office at my company. Ended up missing a flight while they argued about it.
When I was traveling about once a month for a company, I would just book an extra stop wherever I wanted to visit for the weekend before going home (usually a friend somewhere). I got a free visit to a friend, and the company got a cheaper flight expense because of the Saturday stay. Everybody was happy. I'm even happier now not traveling so much though.
All the tickets include "weekend stays" but you never spend a weekend in XYZ.
The OP may have used a one way ticket or something for the original trip since airlines don't book more than a year out.