Solution:

In Clock

Add two hours to eleven o'clock, you get one o'clock.

Solution:

Stop imagining

Solution:

The peahen lays eggs

Solution:

The watchman had been sleeping on the job. Otherwise, he would not have been dreaming.

Solution:

I am a Postbox

Remove as many letters as possible, still postbox remains the same.

Solution:

JASON

July(J)
August(A)
September(S)
October(O)
November(N)

Solution:

Double Letters

Solution:

1:45

The man gave away a total of 25 cents. He divided it between two people. Therefore, he gave a quarter to two

Solution:

I have written 'your exact weight' on the paper.

Solution:

A man, who crawls on all fours as a baby, walks on two legs as an adult, and walks with a cane in old age.

Of course morning, noon, and night are metaphors for the times in a man's (person's) life. Such metaphors are common in riddles. There were two Thebes, apparently this Thebes was the one in Greece. And this Sphinx was apparently not the one at Giza, in Egypt.