How many tours a day do they have?

I can easily count 8-9 ok n the grand tour. During daylight savings time.

From 10am to 4pm the "Grand room" tours are every hour. But they have many different tours to choose from.

Every 20 min from 9AM until 6 pm

If I remember correctly it's like every 2 hours I think it was like from 8 a.m. to 6 p.m. I'm not sure