Revised Standard Version and Good News Translation begin a new paragraph here since the subject matter changes.

Into the tent: The only tent mentioned so far has been Holofernes’ tent, the one they are already in. Good News Translation properly translates “a tent.” Even “another tent” would be allowable here since we are explicitly told in 14.17 that Judith had been staying in a different tent from Holofernes.

According to the Greek text, Judith apparently lies awake awhile. She sleeps until midnight, but she does not rise until just before the morning watch. She is carefully awaiting her time. In Old Testament times the night (6 p.m. until 6 a.m.) was divided into three watches of four hours each (see Jdg 7.19). (In New Testament times the Roman system of four watches of three hours each would be adopted; see Mark 13.35.) The morning watch the author speaks of here would begin about 2 a.m. At the time of the exodus, God acted against Pharaoh’s army in the morning watch (Exo 14.24). Perhaps this was thought of as a time of revelation. Good News Translation and Contemporary English Version have some errors in this verse. Judith does not sleep until just before dawn. She sleeps until midnight, and rouses Holofernes (see verse 6) around 2 a.m. As Good News Translation and Contemporary English Version have it, Judith would be going into the valley at daylight, which is not the intention of the story as she states in 11.17. She does this at night, and starting out at the beginning of the morning watch, about 2 a.m., would allow this. The division of sentences in Revised Standard Version is more helpful than in Good News Translation. She sleeps until midnight. Time passes with a sentence break. Then she gets up…. One could say “About two hours later she got up,” or even “About two o’clock…” if one does not mind bringing in modern terminology.

Quoted with permission from Bullard, Roger A. and Hatton, Howard A. A Handbook on Judith. (UBS Helps for Translators). New York: UBS, 2001. For this and other handbooks for translators see here.