Note 48 — II. OUR DUTIES. (continued 2)

Four weeks and one or two days make one month, ‏חדש‎ or ‏ירח‎. The length of the month is determined by the duration of one revolution of the moon round the earth. Such revolution is completed in twenty-nine days and a half.48 As, however, the calendar mouth does not commence in the middle of the day, but at the beginning of the evening, it was necessary to add half a day to one month, and to take off half a day from the next. The months have therefore alternately twenty-nine and thirty days.