Single day in early June - Morning/Afternoon vs Afternoon/Evening

Hi all,

I'm booked in with my family (children 6 & 10) for the first Wednesday of June next year. We're staying in the city so will come out on the RER.

I'm feeling like a full day, morning to evening/night will probably be too much for the kids so am thinking about either doing morning/afternoon or afternoon/evening.

I guess the upside of going earlier is that it might be a bit quieter in the morning and the kids will be full energy but if we went later we could see the lights show which probably wouldn't be until 9pm?

Alternatively are there any good spots to chill out and have a mid-afternoon rest up to recharge?

I'd love any thoughts or insights.

Merci!