Does the time of Fajr (dawn) prayer start after the first Athaan (call for prayer), or the second one?
All perfect praise be to Allah,The Lord of The Worlds The time of Fajr prayer starts after the second Adhan. And Allah Knows Best.
Does excessive sleep during Ramadan invalidate fasting?
Sleeping a lot in Ramadan does not invalidate the fast, but a Muslim may miss out on great rewards from prayer, Quran recitation, and acts of worship due to excessive sleep.
When does the time for Udhiyah begin?
In the Name of Allah, and may peace and blessings be upon our Master, the Messenger of Allah.
The permissible timeframe for Udhiyah (sacrificial offering) begins on the day of Eid al-Adha—the 10th of Dhul-Hijjah—once the sun has risen and a period of time sufficient to perform two brief prayer units (Rak'ahs) and two short sermons (Khutbahs) has passed. This window remains open until the sun sets on the final day of Tashreeq, which is the 13th of Dhul-Hijjah.
Our Master, the Messenger of Allah (peace and blessings be upon him), said: "Every valley of Mina is a place of sacrifice, and slaughtering may be done throughout all the days of Tashreeq." (Narrated by Al-Bayhaqi and Ibn Hibban)
The days of Tashreeq refer to the 11th, 12th, and 13th of Dhul-Hijjah.
The most virtuous time to perform the sacrifice is immediately after concluding the Eid prayer, based on the statement of the Prophet (peace and blessings be upon him): "The first thing we do on this day of ours is to pray, then we return and offer our sacrifice. Whoever does that has acted in accordance with our Sunnah (tradition), and whoever slaughters before that, it is merely meat he has provided for his family; it has nothing to do with the ritual sacrifice." (Reported by Al-Bukhari and Muslim)
What is meant here is an estimation of time rather than the actual performance of the prayer itself, as our Master, the Messenger of Allah (peace and blessings be upon him), used to offer the Eid al-Adha prayer immediately after sunrise.
The sacrifice is valid if performed at any time during these designated days, whether by day or by night, though slaughtering at night is considered disliked (Makruh). And Allah the Almighty Knows Best.
What is the ruling on praying behind a disliked Imam?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
It is mildly disliked (Makruh Tanzihan) for a man—other than the permanent designated Imam (Imam Ratib)—to lead people in prayer if the majority of them dislike him due to a religiously blameworthy reason (Amr Madhmum Shar‘an), such as associating with open sinners (Fussaq), for example. As for the followers who dislike him, the prayer behind him is not disliked for them. However, if less than the majority dislike him, or if the majority dislike him for a reason that is not religiously blameworthy, then his leading the prayer is not disliked. And Allah the Exalted knows best.