وَمَنْ أَدْرَكَ الْوُقُوفَ بِعَرَفَةَ مَا بَيْنَ زَوَالِ الشَّمْسِ مِنْ يَوْمِ عَرَفَةَ إِلَى طُلُوعِ الْفَجْرِ مِنْ يَوْمِ النَّحْرِ فَقَدْ أَدْرَكَ الْحَجَّ
Translation: Whoever attains the standing at Arafat between the sun’s passing its zenith on the Day of Arafat and the rising of dawn on the Day of Sacrifice has attained the Hajj.
The Day of Arafat is 9 Dhu al-Hijjah; the Day of Sacrifice is 10 Dhu al-Hijjah. Both limits of the window matter.