The 16th would be Yom haBikkurim (day of first fruits). He died on Pesakh with the rest of the lambs, He rested on Shabbat in the tomb and rose on the 1st day of the week (on the 3rd day). BTW, I am a member of that ancient Church...
The commencement of this Counting of the Omer was marked in Temple times by the bringing of the Omer offering and ended 50 days later with the festival of Shavuot, as described in the Book of Leviticus:
“You shall count from the day after (morrow) the Sabbath, from the day when you brought in the sheaf (Omer, tied bundle of grain) of the wave offering; there shall be seven complete Sabbaths (seven full weeks). You shall count fifty days to the day(morrow) after the seventh Sabbath; then you shall present a new grain offering to the Lord... and you shall proclaim on this very day, it shall be a holy convocation for you.” (Leviticus 23:15-16,21).
Late in the Second Temple period, there was a famous debate between the three different Jewish factions about the meaning of the Hebrew phrase “morrow of the Sabbath (the day after the Sabbath)” and hence about the timing of Shavuot.
The three factions were the Pharisees who wrote the Mishnah and the Talmud, the Essenes who wrote the Dead Sea Scrolls, and the Sadducees who made up the Temple Priesthood.
All three factions agreed that the “day after the Sabbath” was associated with the Feast of Unleavened Bread, the problem was identifying which “Sabbath day” during the feast of Unleavened Bread, the text was referring to.
Subsequently, the start of the Counting of the Omer is highly contested and led to the festival being observed on different days, four Sabbath days occur during the feast of Unleavened Bread.
The Pharisees argued that Shavuot is to be counted from the first day (15th day of Abib) of the Feast of Unleavened Bread, which is designated as a “Sabbath.”
According to the Pharisees and their modern-day successors the Orthodox rabbis, morrow of the Sabbath” means the morrow of the 1st day of Unleavened Bread and therefore falls on the
16th.
They begin the 50-day count to Shavuot always on the second day of Unleavened Bread, which is the 16th day of the First Hebrew Month.
The result is that the Pharisees Shavuot always falls between the 5th to the 7th day of the Third Hebrew Month (Sivan).
The Pharisees became the predominant surviving faction, after the destruction of the Temple in 70 A.D. among the Jewish leadership and their interpretation is followed by most Jews today and therefore also the most predominant voice and opinion on this matter today, but does not necessarily imply correctness!
The Pharisee interpretation of the starting “Sabbath” of Leviticus 23:15, creates a bigger problem when it comes to the end of the 50-day count. Leviticus 23:16 says,
“Until the morrow of the seventh Sabbath shall you count fifty days.”
Consequently, the Pharisee Shavuot is rarely the “
morrow of the Seventh Sabbath” as required by Leviticus 23:16. Again confirming it NOT
being supported by Scripture, remember the feast of weeks being a formula, it fails the test!
To understand the phrase “morrow of the Passover” we need to define two terms: “morrow” and “Passover.”
The Hebrew word for “morrow” is mi-mocharat which refers to “the morning after.”
The phrase “morrow of the Sabbath” describes Sunday morning, the morning after the 24-hour Sabbath.
Confirmation of the meaning of the phrase “morrow of the Passover” can be found in a verse in the Book of Numbers:
“And they travelled from Ramesses in the first month on the fifteenth of the month; on the morrow of the Passover the children of Israel went out with a high hand in the eyes of all Egypt.” - Numbers 33:3
This verse describes the day of the Exodus from Egypt as both the
15th of the First Hebrew Month and as the “
morrow of the Passover.”
This only proves the Pharisee interpretation of Leviticus 23:15 to be wrong.
This actually presents the evidence to show how they mistakenly interpreted the wrong starting “Sabbath” to the counting of the Omer, leading them to the 49th day that also proved
NOT to be a Sabbath. This alone is enough evidence to correct the starting point of the count.
15 You will count off for yourselves from the morrow after the first sabbath, from the day you bring the sheaf of the wave offering: there shall be seven flawless sabbaths. 16 Until the morrow after the seventh sabbath you shall count off fifty days; then you will bring near an approach present of new grain to Yahweh.
The confusion is cleared up when we trust the Scripture, not the Pharisees.
It is important to highlight the fact that they are confusing the two offerings, first the offering brought by the people and secondly the offering brought by the priest.
You shall not eat any bread or roasted grain or new growth, until this same day when you bring in the offering to your God; it is a permanent statute throughout your generations wherever you may be. Leviticus 23:14
Here the people are instructed to bring in their offering and is completed the moment it is given to the priests and from
Joshua 5:11 it is clear that this occurred before the 15th, freeing them to eat the new harvest, this included the priests in their unofficial capacity on Passover. Celebrating Passover with new produce.
The instruction for the priest to wave the Omer, which took place on the “
morrow of the Sabbath,” the day after the
weekly Sabbath, from that day the priest brought in the sheaf (Omer, tied bundle of grain) of the wave offering; Must lead to the correct seventh Sabbath.
He (the priest) shall wave the sheaf before the Lord so that you may be accepted; the priest shall wave it on the day after the Sabbath. Leviticus 23:11
Now the count starts and there shall be seven
complete Sabbaths (seven full weeks).
… there shall be seven complete Sabbaths. You shall count fifty days to the day after the seventh Sabbath; then you shall present a new grain offering to the Lord. Leviticus 23:15-16
This day clearly MUST be on the first day of the week or Sunday, if not it fails!
Only now do the calendrical dates line up and the other three witnesses (Sadducees, Essenes and now Christians) confirm this to be the first day of the week or Sunday.
Jesus the final confirmation who rose on the
first day of the week or Sunday, the
morrow of the
Sabbath, starting the count and confirming the correct day for the
Firstfruits feast.
1 Corinthians 15:20-23 But in fact, Christ has been raised from the dead, the Firstfruits of those who have fallen asleep. For as by a man came death, by a man has come also the resurrection of the dead. For as in Adam all die, so also in Christ shall all be made alive. But each in his own order: Christ the Firstfruits, then at his coming those who belong to Christ.
So no it's not the 16th.
Trusting this will help.
Shalom