This term has been used twice in the Qura’n. The first time in verse 9 of Surah Taghabun that says: “The Day He will gather you on the day of gathering.” This is the day when it will be clear who the losers will be.
Verse 7 of Surah Shura that says, “That you may warn the mother of the towns and all around it and warn about the Day of Assembly of which there is no doubt.”
It will definitely be the day of gathering because all the earliest and the last, the Jinns and the humans even the angels will be assembled that day. Not only them but even their deeds will be gathered and presented to the court of God.
This name has come in another word in verse 103 of Surah HUD where it says:
“That is the day whereon man will be gathered together.”