New Living Translation
And since you don’t know when that time will come, be on guard! Stay alert!

American Standard Version
Take ye heed, watch and pray: for ye know not when the time is.

Berean Study Bible
Be on your guard and stay alert! For you do not know when the appointed time will come.

Douay-Rheims Bible
Take ye heed, watch and pray. For ye know not when the time is.

English Revised Version
Take ye heed, watch and pray: for ye know not when the time is.

King James Bible
Take ye heed, watch and pray: for ye know not when the time is.

World English Bible
Watch, keep alert, and pray; for you don't know when the time is.

Young's Literal Translation
Take heed, watch and pray, for ye have not known when the time is;

Mark 13:33 Additional Translations ...