Tokyo fireflies in Shibuya

From the link below, I note that the Botanical Garden Fureai will be holding its annual fireflies evening from 19 to 23 June 2019.
http://www.city.shibuya.tokyo.jp/eng/city_news/pdf/20190501pdf/p2.pdf

From Wed-Fri, it seems the event will be held at 4-6pm. Over the weekend, it will be 7-9pm. As I might not be free over the weekend, I'm considering going there on one of the weekdays. However, I'm wondering whether fireflies can be seen in daylight. I really want to see the glow of the fireflies.

Has anyone attended before? Could you please shed some light? Thank you!

You can�ft see the glow in bright daylight. Also you best go at the times they indicate because then they will have street lights dimmed down or turned off.

I also actually think that they breed the fireflies for the occasion. So you could not likely see them on other days.

Enjoy!

I went a couple of years ago, and it's an interesting experience.

It has nothing to do with streetlights though - it's all indoors, in a very dark, curtained-off interior space inside the building where the Botanical Garden is located. (It's an indoor botanical garden.)

I think they might ask that visitors don't wear perfume or cologne, and of course make sure you haven't used any mosquito repellent or anything like that recently.

Oh, I see. I don�ft know the one in Shibuya. I went to one along a small river close to Kugayama station some years ago, which was outside. I erroneously assumes that Shibuya would be outside as well.

Yes this one is indoors.
Also they ask:
(1) Please do not use any light-emitting devices, such as cell phones, smartphones, cameras, or videos.
(2) Please refrain from bringing in (kids) shoes that have blinking lights on them.
(3) Please do not use any bug/mosquito repellent/insecticide.