'Day of Salvation' in the Bible

Thus saith the LORD, In an acceptable time have I heard thee, and in a day of salvation have I helped thee: and I will preserve thee, and give thee for a covenant of the people, to establish the earth, to cause to inherit the desolate heritages;

"Many nations will join themselves to the Lord on the day of salvation, and they will also be my people. Indeed, I will settle in the midst of you all." Then you will know that the Lord who rules over all has sent me to you.

And being also co-laborers we exhort you not to receive the grace of God in vain,??2 for he says, In an acceptable time I heard you, and in a day of salvation I helped you; behold, now is an acceptable time, behold, now is a day of salvation,??3 giving no offense in any thing, that the ministry may not be blamed,

(For he saith, I have heard thee in a time accepted, and in the day of salvation have I succoured thee: behold, now is the accepted time; behold, now is the day of salvation.)

And do not give grief to the Holy Spirit of God, by whom you were marked for the day of salvation.