Tafsir of Al-Burooj 85:2

And the Promised Day—that is, the day that has been promised—is the Day of Resurrection, by the consensus of the exegetes.

It has been said: Perhaps it is the day on which people emerge from their graves, for He, the Glorified, has said: "They will emerge from the graves rapidly, as if they are rushing toward a target; their eyes humbled, humiliation covering them. That is the Day which they were promised." Or it is the day the heaven is folded like the folding of a scroll for the records.

It has also been said: It is possible that it refers to the day of the Prophet's (may Allah grant him peace and honor) intercession, as indicated by the word of the Almighty: "It is expected that your Lord will raise you to a praised station."

It is not hidden that all of these are included within the Day of Resurrection.