I recently had a two day trip that backed up to a four day trip, where I'd spend one night home after the end of the two-day, then begin the four day trip. Due to weather, cancellations, etc. I ended up stuck in an outstation for an extra night. The company changed my schedule to make it one big trip, under a single pairing number, in order to get me started on the four day ASAP upon returning to base. Is this legal?

When trying to pick up open time, I'm often denied for pairings that are too close together, but I guess the company doesn't have a problem with simply combining them when it suits their needs.