Sometimes the cloud remained only from evening until morning, and when it lifted in the morning, they would set out. Whether it was by day or by night, when the cloud was taken up, they would set out.
Jewish Publication Society of America Version (JPS1917) - Numbers 9:21 >And sometimes the cloud was from evening until morning; and when the cloud was taken up in the morning, they journeyed; or if it continued by day and by night, when the cloud was taken up, they journeyed.