Conditions for the validity of Salaah

Q: What is time of zawal and when does it start and end?

Q: If someone performs his salaah facing the wrong direction, away from the qiblah, does he have to repeat his salaah?

Q: I completed my Fajr Salaah at 6:16 AM. The time listed for sunrise on the perpetual timetable is 6:17 AM. Was my Fajr Salaah valid?

Q: Is it permissible to combine 2 prayers? Meaning, is it permissible to pray zuhr and asr during the time for zuhr? or pray zuhr and asr during the time for asr?

Q: Can we make niyyat/intention for chaast/ishraaq/hajat/shukur/taubaa when performing salaatul tasbeeh?

Q: Our madrasah teacher once told us that we should wait for a while after Azan and pray around 10-15 mins later (i.e. she was trying to say one shouldn't immediately start praying after Azan). Is it true?

Also, my father told me that there's a Hadith that says that one should quickly pray after Azan. Is there such a Hadith?

Q: Is it permissible to pray asr salaah during the last 20 minutes between asr and maghrib? (If I didn’t deliberately delay it).

Q: Sometimes, when I am in a hurry, I make a wrong intention before I start my salaah. For example, when I am supposed to offer Asr, in a hurry I make the intention of zuhr and start my prayer. I then realise this mistake during my prayer. What should I do?

Q:

1. If sunset is 6.40, at what time should Salah be performed?

2. If sunrise is 6.25, what is the end time of Fjar Salah?

3. If magrib Salah is performed a few minutes early, will it be valid?

4. If in the absence of a watch, how do we look at the sky to know fajr and maghrib salaah times?

Q: If a person prayed without using their Qibla compass, but estimated the Qibla location, but found out they prayed in the opposite direction, is their salat valid?