وَمَنْ أَحْرَمَ بِالْحَجِّ، فَفَاتَهُ الْوُقُوفُ بِعَرَفَةَ حَتَّى طَلَعَ الْفَجْرُ مِنْ يَوْمِ النَّحْرِ، فَقَدْ فَاتَهُ الْحَجُّ.
Translation: Whoever enters ihram for Hajj but misses the standing at Arafat until dawn on the Day of Sacrifice has missed that Hajj.
The Day of Sacrifice is 10 Dhu al-Hijjah. Its dawn marks the end of the standing window.
The ruling concerns someone already in Hajj ihram. Intention or arrival in Makkah cannot substitute for being at Arafat in the prescribed period.