Reserving Times at Paris Museums

The Jacquemart-André was very crowded when friends were there during the Botticelli exhibit a couple of weeks ago. You aren't giving this museum (and tea room) enough time if you are off to the Palais Garnier right afterwards. Those are the two reservations that are a little harder to get, and you need to space them more.
As for the Louvre and Cómodo, you can reserve at the last minute, which means you should be able to be on time.
The guards are dealing with so much chaos between la Pass, security, timed tickets, people arriving early, late, the wrong day, so do your best for their sake.

Venues have a designated maximum number of visitors that are permitted at any one time, therefore there isn’t usually much flexibility on entrance. You may get away with 5-10 minutes leeway, but probably not 30, otherwise it defeats the point of timed entries.

I haven't noticed that yet, Aimee, but maybe it's because I haven't actually bought a ticket yet. I'll look for that.
Thanks for the info all!

On my recent trip I was able to book my Louvre tickets the day before BUT I had also looked another day and the timed entries were completely sold. I encourage you to look at the official ticketing site and see what times are available for the day/s you are interested in.

I actually went 3 times over a month. The 2nd time was a Sunday and was very busy. I had a 1200 appointment and was in line just after 11. The security person who was walking back along the line reviewed my ticket wanted me to leave the line but I pointed to the line behind me (long that day) and the reservation time for the Athens exhibition and she shrugged her shoulders and walked off. I tried not to make eye contact again, lol.

I also found Jacquemart-Andre very busy. I definitely would make reservations there if the Botticelli exhibition is still going. There were 3 buses that pulled up and discharged groups that went directly into the museum. If you decide to do to do J-A and Camondo on the same day (they are pretty close), I’d suggest J-A when they open, lunch at the neat J-A cafe as soon as they open (including wine and a delicious dessert, lol), then stagger over to Camondo, lol!!

I did not make it to Camondo this trip so not sure how busy they are.

When we were there in September the Musee d’Orsay have us a 30 minute window before/after but you best check individually with each when you make the reservation.