Deuteronomy 16:1-8 has been cited by some as supporting an Abib or Nisan 15 Passover due to its mentions of Passover. However, upon closer examination, it becomes clear that these instructions do not pertain to Passover, which is assigned to Abib 14. The context and specific commands in this passage align instead with the Days of Unleavened Bread, particularly the Night to be Much Observed. Numbers 33:3 confirms that Israel departed from Rameses on the fifteenth day of the first month, the day after Passover, which is the first day of Unleavened Bread. This indicates that the day to be remembered in Deuteronomy 16 is the 15th, not the 14th. Furthermore, the instructions in Deuteronomy 16, such as the location of the sacrifice and the method of preparation, contradict the requirements for Passover as outlined in Exodus 12, reinforcing that an Abib 15 Passover does not align with the scriptural directives for the 14th.

The observance of Passover is clearly instructed to be on the fourteenth day of the first month, which is Nisan 14, at twilight or evening, as supported by multiple scriptures. God defines the start of a day as beginning with evening, followed by the morning, establishing that evening begins at sunset. In contrast, some advocate for Nisan 15 as the day for Passover, which contradicts the distinct separation of Passover and the Feast of Unleavened Bread, as Numbers 28:16-17 and Leviticus 23:5-6 assign these observances to separate days, with the Feast of Unleavened Bread beginning on the fifteenth day. Observing Passover on Nisan 15 causes an overlap that goes against these clear instructions. Furthermore, Exodus 12:5-6 specifies that the Passover lamb is to be kept until the fourteenth day and killed at twilight, reinforcing that Nisan 14 is the correct time for this observance.

The events in Genesis 14 took place on Nisan 14 just after the sun set. The preparations for what was going to take place on the 15th were all arranged by the time the 14th was ending. The first holy day had begun as the sun was going down. God made the oath that His word could be absolutely trusted on that day. He made this vow so that Abraham would be impressed that God did this very thing right before his eyes. Israel left Egypt at night just as the 15th the Night to be Much Observed was beginning. Both Passover and the first day of Unleavened Bread were observed exactly 40 years to the day after leaving Egypt. The selfsame day indicates an exactly dated anniversary.

The children of Israel left Egypt on the 15th in the month of Abib. The Bible shows they did not leave on Passover. They were still in their houses on the 14th. The leaving by night pertained to the first day of Unleavened Bread on the 15th. It was the night part of the 15th day of the month that they left Egypt. The Egyptians were burying their dead late on the daylight portion of the 14th toward sunset as the Israelites were beginning to move out of Rameses. The phrase the month of Abib is connected with Unleavened Bread and the Exodus. The Israelites left on the 15th in the month of Abib. They were to sacrifice an animal from the flock and the herd at ba erev on the 15th and eat it in celebration of their coming out of Egypt. They were celebrating the Night To Be Much Observed. God commanded the people to make the sacrifice at the beginning of the Days of Unleavened Bread right after ba erev had occurred. It was on the 15th. The people were to sacrifice that animal and then eat it. They celebrated all night long.

Abib/Nisan 15 marks the first day of Unleavened Bread. On this day Israel departed from Egypt at night twenty-four hours after the events of Passover on the fourteenth. The subject of Exodus 12 from verse 37 to verse 42 and continuing through chapter 13 concerns the first day of Unleavened Bread on the fifteenth. This date commemorates the beginning of Israel's freedom as a nation exactly 430 years to the day after God made the covenant with Abraham. God watched over the people as they left and continued to provide for them through the wilderness. The same day saw a partial fulfillment when Israel entered the land and observed the festival there. The first day of Unleavened Bread draws attention to freedom from spiritual bondage and God's ongoing providence.

Abib 15 or Nisan 15 is the first day of Unleavened Bread. This day memorializes distinctive events including prophecy, promises, and fulfillments made by God. Abib 15 is a Sabbath on which a holy convocation occurs and no servile work is done. God directly calls Abib 15 a feast. Israel left Egypt on Abib 15. The departure occurred at the beginning of Abib 15 as darkness was just beginning. Israel left Egypt at night on the 15th. The eating of unleavened bread begins as the 14th ends and the 15th begins. Unleavened bread is to be eaten until ba erev on the 21st. The Days of Unleavened Bread begin as the 14th ends and the 15th begins. Both the 14th and the 15th are days to remember. The events of Abib 15 are to be remembered and thus both days are commanded to be kept.

The fifteenth day begins when ba erev occurs at the end of the fourteenth. Passing over occurs on the fourteenth and coming out occurs on the fifteenth. The Exodus begins on the fifteenth. The Israelites go out on the fifteenth. They depart the day after Passover. God acts on the fifteenth. The Passover takes place on the fourteenth and the going out of Egypt takes place on the fifteenth. The fifteenth Passover advocates claim that the Exodus begins the moment the Israelites go out of the doors of their houses. The fifteenth Passover advocates squeeze events that God intended to take twenty four hours into nine to eleven hours. The fifteenth Passover advocates claim that all the spoiling is done before Passover ever takes place. The fifteenth Passover advocates claim that boqer arrives right after midnight. The fifteenth Passover advocates are confronted with a serious problem as a result of the squeezing of the events of the Passover into a nine to eleven hour period. The fifteenth Passover advocates reduce what God intended to be an eight day period of time into seven days and a few extra hours and rename the whole thing Passover.

The 14th of the first month, Abib, was the Passover, and the 15th was a feast day, or annual holy day. The 15th was the first of seven days of unleavened bread. The 15th of Abib or Nisan remains an annual holy day. The Jewish people observe the feast on the eve of 15th Abib. The Lord's supper or New Testament Passover should be observed after sunset on the evening before the Jewish people of today celebrate their feast.

The Feast of Unleavened Bread starts on Abib/Nisan 15 and lasts for seven days until Abib/Nisan 21. The exact same instruction appears elsewhere, showing that the Feast of Unleavened Bread starts on the fifteenth and lasts for seven days until the twenty-first. The prince's offering is for the first day of the Feast of Unleavened Bread on Abib/Nisan 15, not the Passover.