Time of Standing at ʿArafah

Answer—and Allah grants success: The time for standing, according to the madhhab, is from noon (zawāl) on the ninth day of Dhū al-Ḥijjah until the dawn of the Day of Sacrifice. Whoever stands at any time within this interval has caught the Hajj and his standing is valid; whoever misses it has missed the Hajj.
Some scholars said: The time for standing is from the beginning of the day of ʿArafah until the break of dawn on the Day of Sacrifice, and they adduced as evidence his statement, May Allah bless him and his family and grant them peace: “And he came to ʿArafāt before that, by night or by day.”
It is answered that consensus has been established that the time for standing begins at noon; thus the ḥadīth is to be understood in light of that.
I say: The preponderant view is that the standing begins from noon, for the Prophet (May Allah bless him and his family and grant them peace) did not come to the standing place except after noon, as in the ḥadīth of Jābir describing his Hajj, May Allah bless him and his family and grant them peace. It is not far-fetched, however, that the early part of the day be a time for one in necessity, just as the night is a time for him; in this there is a reconciliation between the evidences.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.1