Salaah

When does Tahajjud time end?

Q: I have two questions which I kindly request you to answer me.

1. I have doubt regarding tahajjud Salaah. I want to know when it exactly ends. Say the fajr Salaah starts at 5.23 am in where I live , now. Till wheat time then can we pray tahajjud Salaah? I want to know the timing so I can rectify if I make any mistakes.

2. Can we recite salawatun naariya with a particular niyat to be fulfilled? Where I live people recite it 4444 times with a particular niyat he or she has. Is it permissible?

Performing qasar Salaah while travelling to one's destination

Q:

1. If someone intends traveling to a place more than 55 miles (i.e. 88 km) from his hometown but intends staying at his destination for more than 15 days, will he do qasr while traveling to that place?

2. If a person intends going to a place more than 55 miles (i.e. 88 km) from his hometown. After reaching he intends to stay for 15 days. Later on he changes his mind and intends to stay for 2 days. Will he be musafir or muqeem?