Yaum means Day. Today is Yaum ul Arafah. It’s the ninth day of Zil Haj (according to the Lunar Calendar). The day after is Eid ul Adha, a major Islamic holiday. It’s the second day of Haj (the pilgrimage to Mecca which is binding on all Muslims who have the means to do so).
Fasting on this day is an expiation for two years.
Today is a day of Mercy from Allah. Your prayers are answered. Last night I asked Son to tuck away his phone for a day, and concentrate more on prayers, and dua. Son is addicted to his iPhone. It’s a mega tussle to get his attention once he is on his iPhone.
It’s the day on which Islam was perfected for us.
Flowers and Breezes 