My youngest ALWAYS starts to get tired at this time, he doesn't nap through the day as he is too active (he is 2).
He normally goes to bed between 6.30 and 7pm and at 5pm he is shattered. Cries, is very clumsy etc etc. He wakes about 7.30am.
Cant do anything with him to calm him down.
God i hate this part of the day lol.