MANY SCENARIOS – ONE TRUTH
Regretfully there seems to be much confusion in the Messianic movement over when the Passover actually begins. It’s really such a shame when you realise the simple solution. Let’s examine some of the models…

SCENARIO # 1
If one were to follow the Jewish tradition, one would wait till the end of the 14th day of Abib and perform the seder as the sun goes down which actually overlaps into the traditional 15th day (A day for the Jews starts at evening).
This tradition does NOT conform to what the Scriptures teach:
Leviticus 23:5-6 “In the first month, on the fourteenth day of the month, between the evenings, is the Passover to YHWH. 6 ‘And on the fifteenth day of this month is the Festival of Unleavened Bread to YHWH – seven days you eat unleavened bread.”
‘Between the evenings’ is sometimes taught (due to pharisaical tradition) to be anywhere between 3pm and 6pm. If one simple takes their instruction from Torah rather than oral tradition, then ‘between the evenings’ is obviously in the twilight of the evening:
Deuteronomy 16:6 “You slaughter the Passover in the evening, at the going down of the sun, at the appointed time you came out of Mitsrayim.” 
According to Leviticus 23:7 the 15th is a Sabbath; therefore if the children of Yisra’ĕl were to fulfill the requirement of the first Passover to burn the leftovers before morning, this method also would be in direct conflict with the command not to light a fire on Sabbath:
Exodus 35:3 “Do not kindle a fire in any of your dwellings on the Sabbath day.” 

SCENARIO # 2
In an effort to ammend this glaring problem some Messianic believers have moved the Passover to the evening at the start of the 14th rather than the end to celebrate the Passover according to Exodus 12:42.
“It is a night to be observed unto YHWH for bringing them out of the land of Mitsrayim. This night is unto YHWH, to be observed by all the children of Yisra’ĕl throughout their generations.” (Exodus 12:42)
This practice however presents another difficulty in itself by leaving 12-24 hours of nothing before the 15th when the 7 days of unleavened bread is to be honoured. If one continued unleavened bread from the beginning of Passover to the 21st as commanded in Exodus then one would end up with 8 days of unleavened bread!
Exodus 12:18-19 “In the first month, on the fourteenth day of the month, in the evening, you shall eat unleavened bread until the twenty-first day of the month in the evening. 19 ‘For seven days no leaven is to be found in your houses…”

All these problems could be rectified if only believers would accept the simple truth of Scripture rather than follow traditions!
The solution is simple…

SCENARIO # 3
A DAY DOES NOT START AT NIGHT!
As you will see as we continue, there is only ONE model that fits ALL the Scriptures…
(For a Scriptural study with over 25 Scripture proofs click the link below)

WHAT THE SCRIPTURES SAY
Before we look at the various scenarios, let’s examine all the relevant Scriptures:
The Scriptures reveal this about the lamb offering and the timing of the Passover:
Exodus 12:6 “And you shall keep it until the fourteenth day of the same month. Then all the assembly of the congregation of Yisra’ĕl shall kill it between the evenings. 7 ‘And they shall take some of the blood and put it on the two doorposts and on the lintel of the houses where they eat it. 8 ‘And they shall eat the flesh on that night, roasted in fire – with unleavened bread and with bitter herbs they shall eat it. 9 ‘Do not eat it raw, nor boiled at all with water, but roasted in fire, its head with its legs and its inward parts. 10 ‘And do not leave of it until morning, and what remains of it until morning you are to burn with fire. 11 ‘And this is how you eat it: your loins girded, your sandals on your feet, and your staff in your hand. And you shall eat it in haste. It is the Passover of YHWH 12 ‘And I shall pass through the land of Mitsrayim on that night…”
Note: The 14th is the day of the offering and is called the “Passover of Yahweh” when He passed through the land “that night“! There is no question. the night of the 14th is Passover.

Exodus 12:29-51 “And it came to be at midnight that YHWH smote all the first-born in the land of Mitsrayim, from the first-born of Pharaoh who sat on his throne to the first-born of the captive who was in the dungeon, and all the first-born of livestock. 30 And Pharaoh rose up in the night, he and all his servants, and all the Mitsrites. And there was a great cry in Mitsrayim, for there was not a house where there was not a dead one. 31 Then he called for Mosheh and Aharon by night, and said, “Arise, go out from the midst of my people, both you and the children of Yisra’ĕl. And go, serve YHWH as you have said…
41 …And it came to be at the end of the four hundred and thirty years, on that same day it came to be that all the divisions of YHWH went out from the land of Mitsrayim. 42 It is a night to be observed unto YHWH for bringing them out of the land of Mitsrayim. This night is unto YHWH, to be observed by all the children of Yisra’ĕl throughout their generations…
51 …And it came to be on that same day that YHWH brought the children of Yisra’ĕl out of the land of Mitsrayim according to their divisions.”
Note: The Israelites observed the Passover on the night of the 14th so that by the morning of the 15th they on their way out of Egypt as per Numbers 33:3
Numbers 33:3 “So they departed from Raʽmeses in the first month, on the fifteenth day of the first month, on the morrow of the Passover the children of Yisra’ĕl went out with boldness before the eyes of all the Mitsrites.”
Note: the 15th is described as being the morning (morrow) after the Passover.

Leviticus 23:5-6 “In the first month, on the fourteenth day of the month, between the evenings, is the Passover to YHWH. 6 ‘And on the fifteenth day of this month is the Festival of Unleavened Bread to YHWH – seven days you eat unleavened bread.”
Note: ‘Between the evenings’ is a Heḇrew idiom that according to the Pharisees means: ‘between the decline of the sun immediately after midday and sunset, that is approximately 3 pm. in the afternoon’.
If that is the case; scenario # 2 would be commencing on the 13th.

Deuteronomy 16:1-6  “Guard the month of Aḇiḇ, and perform the Passover to YHWH your Elohim, for in the month of Aḇiḇ YHWH your Elohim brought you out of Mitsrayim by night. 2 “And you shall slaughter the Passover to YHWH your Elohim, from the flock and the herd, in the place where YHWH chooses to put His Name. 3 “Eat no leavened bread with it. For seven days you eat unleavened bread with it, bread of affliction, because you came out of the land of Mitsrayim in haste – so that you remember the day in which you came out of the land of Mitsrayim, all the days of your life. 4 “And no leaven should be seen with you in all your border for seven days, neither should any of the meat which you slaughter in the evening on the first day stay all night until morning. 5 “You are not allowed to slaughter the Passover within any of your gates which YHWH your Elohim gives you, 6 but at the place where YHWH your Elohim chooses to make His Name dwell, there you slaughter the Passover in the evening, at the going down of the sun, at the appointed time you came out of Mitsrayim.”
Note: Unleavened bread must continue immediately after Passover for 7 days.

Just in case this is not clear enough, let’s examine some graphic charts of the three scenarios:

SCENARIO # 1 (DAY STARTS IN THE EVENING)

As you can see, this fits with Unleavened bread following directly after Passover, but on the 15th night rather than the 14th according to Scripture.

SCENARIO # 2 (DAY STARTS IN THE EVENING)

This scenario attempts to fulfill Pesach on the evening of the 14th, but what about the daylight of the 14th?
This model of the Passover doesn’t fit with the account of the Israelites making the Exodus the following morning, nor does the festival of Unleavened Bread succeed Passover.

SCENARIO # 3 (DAY STARTS IN THE MORNING)

As you can plainly see, this is the only scenario that actually fits with ALL the Scriptures.
By coming to the simple understanding that Yahweh called the LIGHT “day” (Heb. yom) a believer has no difficulty in honouring Yahweh’s Moedim in confusion.

Genesis 1:5 “And Elohim called the light ‘day’ and the darkness He called ‘night.’ And there came to be evening and there came to be morning, the first day.”
Simply scroll back up and read all the Scriptures with this definition: when the text reads DAY – think “LIGHT”, andwhen the text reads NIGHT – think “DARK”
We are children of the light and need not walk in darkness.

May Yahweh bless you as you seek to honour Him through your obedience.