What is the right time to sleep?

Well got a nice incident to start of the blog with. It happened last weekend. My cousin had come how with his 2.5 year old twins. It was just another wonderful eve of playing with my nieces. Was in general having a good time. And then came the googly that I never picked up. It was about 7:30 in the eve. One of the girls was sitting on the floor. The other one playing with my dad in another room. She was surrounded by mom, sis, manni(the kids mom) and me. She was sitting cross-legged on the floor. So I tried to sleep on her lap. Then came the most innocent statement that u will hear only from a kids mouth, which sent the whole room into a burst of laugh and a look of total innocence from the kid. “Ippo poi thunguvala”.