For context:

We'll be in Paris from August 23 to 27 and then Normandy for a few more days afterwards. There are a few things that we want to do that require "seeing the city lights" etc. For example; View from Montmarte, from Eiffel Tower, from Arc de Triomphe, Chartres, Versailles and MSM (Mont St Michel). I can see that sunset is around 8:50pm during those dates - lets say I am doing a 6:30pm dinner seating on the Tower - it seems to me that it will still be quite light at that time of night and I won't get the city of Light experience that I am hoping for - is this correct? I'm assuming that most people eat after 8pm for this reason??

Is there an easy way to set my expectations of when it gets dark?

Many thanks

I don't think that's the reason most people eat at 8pm because in the winter it gets dark quite early. We were there in May and we had to get used to staying up later to see the lights. I would plan on darkness being after 9pm. This wasn't easy because we are early birds.

It will be dark by 21:30 in late August. That is the starting time for the outdoor cinema at La Villette in any case.

It will be dark by nautical dusk time darker still at astronomical.

https://www.timeanddate.com/sun/france/paris?month=8

And no, people do not plan their dinner time by whether it is light or dark. Maybe some tourists do but in that case people who have booked dinner for 18:30 would be the ones who are afraid to be out after dark in August.

Thanks all

I'm thinking of getting to the Arc de triomphe at around 7:30 then a 9pm dinner sitting for the tower instead of the 6:30, and I'm thinking of that it'll be ok to get to MSM after 7pm and staying overnight. Fee free to give me better advice on this

Thanks again

I can't identify with wanting to see city lights at night, maybe because I was raised in a major city.
that said, we REALLY enjoyed taking a batobus boat ride down the Seine, which arrived at the dock at the base of the Eiffel Tower at 8:55 PM one September.
JUST as our feet hit the dock, the mayor, probably, turned the lights on the Eiffel Tower.....just for us.......amazing...........twinkling like crazy............wonderful experinece!!!!!!

The lights on the Eiffel Tower twinkle on the hour for about 5 minutes, after dark of course. It is magical.