The standing at আরাফাত (wuquf) is the greatest pillar of হজ্জ, as নবী করীম (সাল্লাল্লাহু আলাইহি ওয়া সাল্লাম) said: 'হজ্জ is আরাফাত.' Its time begins after zawal (when the sun passes its zenith) on the 9th of Dhul-Hijjah জমহুর উলামাদের মতে, and extends until the dawn (fajr) of the 10th of Dhul-Hijjah. A হাজী who is present at আরাফাত for even a moment during this time window has fulfilled the pillar of হজ্জ.
Sheikh Ibn Baz explained that the Sunnah is to arrive at আরাফাত before zawal, pray Dhuhr and Asr combined and shortened, and remain there supplicating until sunset. However, a হাজী who arrives late — even in the last moments before fajr of the 10th — has caught আরাফাত and their হজ্জ is valid. নবী করীম said: 'Whoever comes to আরাফাত before dawn on the night of Jam' (মুযদালিফা), his হজ্জ is complete.' This hadith establishes that the nighttime of the 9th is also valid time for wuquf.
Sheikh Ibn Uthaymeen noted that while arriving late at night is valid, the হাজী who only stands at আরাফাত at night misses the Sunnah of daytime standing and the great merit of দোয়া on the afternoon of আরাফাত. He মুস্তাহাব every effort to arrive during the daytime. If a হাজী arrives after sunset but before fajr, their standing is valid but they should offer a dam (sacrifice) according to some scholars, as they missed the daytime standing. However, the majority hold that no dam is required as long as any part of the wuquf window was caught.