NASB 1995
"For then there will be a great tribulation, such as has not occurred since the beginning of the world until now, nor ever will.

American Standard Version
for then shall be great tribulation, such as hath not been from the beginning of the world until now, no, nor ever shall be.

Berean Study Bible
For at that time there will be great tribulation, unmatched from the beginning of the world until now, and never to be seen again.

Douay-Rheims Bible
For there shall be then great tribulation, such as hath not been from the beginning of the world until now, neither shall be.

English Revised Version
for then shall be great tribulation, such as hath not been from the beginning of the world until now, no, nor ever shall be.

King James Bible
For then shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.

World English Bible
for then there will be great oppression, such as has not been from the beginning of the world until now, no, nor ever will be.

Young's Literal Translation
for there shall be then great tribulation, such as was not from the beginning of the world till now, no, nor may be.

Matthew 24:21 Additional Translations ...