I scheduled soccer (which is supposed to run til 430) and then I scheduled swimming. NOW swimming I had tried to book for a Monday but that didn't work, so the only available days were Thursday or Saturday. And I had forgotten about soccer at the time and was feeling pressured... so I went with Thursday ONLY to realize that I had slightly double booked myself.
So what ended up happening was that the lad left soccer 10 minutes early so we could get to swimming.
My mom-in-law, who is a marvellous lady by the way, would have taken the lad swimming if she needed to, but she didn't really want to. She was delighted that she didn't have to break up her play day to take the lad swimming. And it worked out for us as missing 10 minutes of soccer didn't really impact on the lad over much and meant we only had to drive to London twice in one week.