The standing window runs from after noon on 9 Dhu al-Hijjah through dawn on 10 Dhu al-Hijjah.
Case 1: arrival at Arafat during the night following the day of 9 Dhu al-Hijjah, before dawn of the 10th; the standing is attained within its time.
Case 2: first arrival after dawn on the 10th; the rite has been missed.
Both the legally defined time and the boundaries of Arafat matter.