It can be as many as 2-3 days of side effects, and some people have trouble on Day 1, some only on Day 2. It just depends. And the J&J is still the least available, especially after the setbacks (both the pause and the destroyed doses).
Basically you should get whatever you can get whenever you can get it as soon as you can get it, with no other considerations. As it happens I delayed my own second dose by two days to better suit my work schedule, but I also have very little exposure to co-workers (i.e. none), don't have to travel etc, and it was still five days earlier than my original appointment (I kept changing it as slots became available).
Of course the other possibility here is that the Phillies did in fact manipulate the IL. That is, "hey Didi, as long as you can't play today here's that shot appointment!"