Shibuya Sky - Day or night?

We only have time to visit Shibuya 1 time, either first thing in the morning (9am?) or before it closes (9:30pm?). Which one is recommended? Also how much time do we need to allocate? Thanks.

Night is better.Night is charming.
Here my gf song her best song "waiting for tonight"

Yeah, 9 am is too early. Not even sure if shops would be open yet. I donft think so. Need to have a look next time I come through Shibuya in the morning. But at that time itfs mostly delivery vans, drunken people from the night before and people commuting to work/school.

How long you need in Shibuya totally depends on what you want to do. Id say an hour should be the minimum not including any shopping.

Is the OP asking re the view from the tower?

Regardless, yes I think night is nicer.

Actually, what is the best time to go if we were to go near the night, on a weeknight (Tuesday)? Is it better to go at 9pm so presumably there will be less people, or right before the sunset? And if the latter, what time is sunset/best time to enter the place?

Also, how big is the place? Is 90 min more than enough to do the photoshoot/enjoy the view?

Nighttime is always better to view the Tokyo cityscape, or any cityscape of a Japanese city, in general. At least in my opinion. As for allocation time, about an hour to hour and a half should be enough.

Spend the day and the night. Shibuya's shops and stores aren't fully open until noon, so if you get there too early you won't have as much to do. There is a Midorizushi (sushi) restaurant on the second floor of the building across from Hachiko (there is a bridge which runs from Shibuya Station to this building. I recommend this restaurant, there is always a line, but it moves quickly, the sushi is good, and reasonable.

You can then go across the street by the ƒXƒNƒ‰ƒ“ƒuƒ‹Œπ·“_ (scramble intersection) and check out Starbucks for Coffee, and the book store. Then just go out and wander, it's more fun to find things by accident than to try and search them out.

What PPs are trying to say (and I agree) donft just go to Shibuya for the view from a tower. Mingle on the ground floor, shopping arcades, streets with the people there.
All in all, without real shopping but with the tower view I would plan on 2-3 h for Shibuya. If you want to have lunch/dinner longer.