Time – Days, Months, and a Year – Before Passover
Biblical units of time are slightly different than the ones we use. Genesis 1 gives day, night, seasons, days, and years; the first use of “months” are in the Flood story with Noah. These units are important in the Passover story, but I am not going into them in depth. (I did a post about the Biblical Calendar; it takes a slightly different direction than what I need here but it is a good read.)
The twenty-four-hour cycle is the same but biblically the day starts at sundown, not sunrise. Joseph Prince said that allows us to start the day resting, think about it! In Exodus 12, the Passover story, the Lamb is killed at twilight – the start of the day. I am sure that I may slip up on specific days/dates; this is another reason that I chose to follow Passover and not Easter.
In Exodus 12 God redefines the Israelite calendar picking a new first month. They have gone back and added up all of the previous generations so their yearly number is over 5000. Since this is marked off by seasons and lunar cycles there is an 11-day difference in length. The High Priest could put in “leap years” to set the year back with the seasons.
On the Jewish calendar, it is the month of Nissan. I have read enough to know that there was a civil and religious calendar, and there are spots in scripture where the civil calendar is used – be careful if you are trying to make a specific point.
The other thing about the biblical month is that it follows the lunar cycle. That makes some of the months 29 days long and some 30 days long. The modern Jewish calendar is interesting; you should do a search and read on it.