Every one his day. — i.e., probably his birthday. (Comp. Genesis 40:20; Genesis 21:8; and in the New Testament Matthew 14:6; Mark 6:21.)
Related Commentaries of Job 1:4
Job 1:4
4 And his sons went and feasted in their houses, every one his day; and sent and called for their three sisters to eat and to drink with them.