I'm trying to make reservations for the Eiffel Tower at 7pm to see sunset at 8pm, but the site won't let me choose anything between 5:30 and 8pm. (I'm trying for September, which isn't on sale yet, but it's the same for sooner months.) Anyone else experience this, or is it maybe a glitch on my Mac?
You can keep trying, especially right away on the day your dates go on sale and you'll probably be able to get tickets. Myself, I wouldn't sweat it. If you go over to the tower and get in line at 6:30 you will most likely be up in plenty of time for an 8:00 sunset. I went on an August evening and only stood in line about 25-30 mins. Reserved time tickets are nice but not necessary.
I booked my tickets for June a month or two ago. I have noticed that my day and the days before and after are sold out now. I noticed the same thing about it not being available even though I was able to get a few layers into the website before it stopped. However, after doing this a few times, I noticed there was a message saying what day my date would be available for purchase. I came back on that date and was able to get my desired reservation time. I hope that helps. Enjoy!!