An Acceptable Time

Having just finished the M. L'Engle book by this title, I now seem to keep coming across this phrase!

From the KJV:
Psalm 69:13But as for me, my prayer is unto thee, O LORD, in an acceptable time: O God, in the multitude of thy mercy hear me, in the truth of thy salvation.
Isaiah 49:8Thus 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;

And from the NIV:
PS 69:13 But I pray to you, O LORD,
in the time of your favor;
in your great love, O God,
answer me with your sure salvation.
ISA 49:8 This is what the LORD says:
"In the time of my favor I will answer you,
and in the day of salvation I will help you;
I will keep you and will make you
to be a covenant for the people,
to restore the land
and to reassign its desolate inheritances,
ISA 49:9 to say to the captives, `Come out,'
and to those in darkness, `Be free!'
"They will feed beside the roads
and find pasture on every barren hill.