Chelsea's Second Leg on Thursday and Arsenal's on Monday?

I wasn't expecting her to be out for as long as she has been, if I'm honest. Scheduling wise, by the way, does anybody know why Chelsea are playing their second leg on Thursday and Arsenal aren't playing until the Monday? I mean, they're supposed to be played on the weekend, right? That's what they're scheduled for. And yes, obviously you can play back to back in the stadiums, but you, for rules, mean that you have to have the away team able to train on the pitch the day before. So then you're working around the schedule of whatever games going on in that stadium on that day. But yes, and they've got