B^eyom = when. It is the figure Synecdoche, by which a part is put for the whole, or the whole for a part (see Appendix 6). What that "part" is must be determined by the context in each particular case.
  In Genesis 2:4, it is put for the whole six days.
  In Numbers 7:84, it is put for the whole twelve days of the dedication of the altar.
  In Leviticus 13:14, it is rendered "when". Revised Version whensoever. Numbers 28:26, see notes.
  In Leviticus 14:57, it is rendered "when", both in Authorized Version and Revised Version. Compare Deuteronomy 21:16. 1Samuel 20:19. 2Samuel 21:12.
  In 1Kings 2:37, it is rendered "on the day", but verse 41 shows that Shimei had been to Gath and back before Solomon executed the sentence (verses 37, 42).
  In Psalm 18:18, it is rendered "in the day", but evidently means at the time when.

  In Isaiah 11:16, it includes the whole period of the Exodus.
  In Jeremiah 11:4, 7, it includes the Exodus and the whole time of giving the law at Sinai. Compare chapters 7:22; 31:32; 34:13.
  In Ezekiel 20:5, 6,¹ it includes the whole time of God's choice of Israel.
  In Ezekiel 36:33, it includes the whole time of rebuilding the waste places of Israel in the future restoration. Compare chapter 38:18.² Authorized Version = at the same time. Revised Version = in that day.
____________________________

  ¹ In verse 6 it has the definite article (bayom), and denotes the specific day when Jehovah delivered them, in contrast with the indefinite past time of His choice.
  ² Here the definite article is used to mark a specific occasion. See Authorized Version.