I know the answer of 1st one:
When the person is sentenced to death by the court the order says he will be hanged on 21st may 2009. So the day 21st may will start after Fajjar ,and he has to be hanged before Dawn ,so that he was hanged exactly at the start of 21st May 2009. Btw the answers the 2nd and 3rd can be given by any lawer like riz or cooljamshed