When do biblical days begin?
Each day ends at sunset and then a new day begins.
Evening IS synonymous with sunset
God first defined days by concluding each creation day with the phrase Genesis 1:5 . . . And the evening and the morning were the first day. Genesis 1:8 . . . And the evening and the morning were the second day etc. etc. The evening or sunset beginning each day. It is for this reason that since creation Gd’s Holy weekly Sabbath day has always been observed from sunset to sunset. Which sunset to sunset 24 hour day was endorsed by Jesus Christ the very Creator himself during his earthly life.
Confirming that evening is the same as sunset, the terms sunset and evening or end of the day are used synonymously in Joshua.
Joshua 8:29 And the king of Ai he hanged on a tree until eventide: and as soon as the sun was down, Joshua commanded that they should take his carcase down from the tree,
Joshua 10:26 And afterward Joshua smote them, and slew them, and hanged them on five trees: and they were hanging upon the trees until the evening. 10:27 And it came to pass at the time of the going down of the sun, that Joshua commanded,
The fact that evening is sunset is also made plain by the law which states that any unclean person must wash and when the evening [used synonymously with sunset] comes, he will be clean.
Deuteronomy 23:11 But it shall be, when evening cometh on, he shall wash himself with water: and when the sun is down, he shall come into the camp again. See also Leviticus 15.
The Passover was to be killed; Between the Two Evenings
Exodus 12:6 And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening [beyn ha’arbayim]. (KJV)
The Hebrew phrase beyn ha’arbayim is translated as “in the evening” above. However, the literal translation of this expression is “between the evenings,” as Jay Green’s English rendering of the Old Testament, A Literal Translation of the Bible (LTB), shows:
Exodus 12:6 And it shall be for you to keep until the fourteenth day of this month. And all the assembly of the congregation of Israel shall kill it between the evenings [beyn ha’arbayim]. (LTB)
Most modern versions of the Bible render beyn ha’arbayim either as “at twilight” or “at dusk.” This phrase occurs 11 times in the Old Testament (Ex 12:6; 16:12; 29:39; 29:41; 30:8; Lev 23:5; Num 9:3, 5, 11; 28:4, 8). The first occurrence, Exodus 12:6, is in reference to the time that Christ commanded the Passover lambs to be slain.
In the Temple period the Mosaic Pharisees, Samaritans, Karaites, and Sadducees [the priests who actually performed the temple service], all taught that “between the evenings” was the time AFTER sunset and BEFORE darkness (Interpreter’s Bible, Ex.12:6; also The Jewish Encyclopedia, art. Passover, page 553).
Jesus Christ kept the weekly Sabbath and annual High Days, Festivals and the Passover by this system, endorsing it and setting an example that we should do likewise.
The Daily Sacrifice
In Numbers 28:3-4 we read of the daily morning and evening sacrifices in the tabernacle. Here the word “evening” is also from the Hebrew: “between the two evenings.” That is, between sunset and full dark.
The Evening Sacrifice WAS FIXED BY THE LAW (Numbers 28:4,8) as “between the evenings” which is the period after sunset and before full darkness, or as many translations put it; in the twilight.
The Hour of Prayer which began at 3 PM, was not the actual evening sacrifice, but was the beginning of the process leading up to the actual offering [burning] of the sacrifice. Again the Mosaic Pharisees, Samaritans, Karaites, and Sadducees [the priests who actually performed the service], all taught that “between the evenings” was the time AFTER sunset and BEFORE darkness (Interpreter’s Bible, Ex.12:6; also The Jewish Encyclopedia, art. Passover, page 553).
In addition, such admonitions as “to show forth thy faithfulness every NIGHT upon an instrument of ten strings and on the psaltery” (Ps 92:2,3) and the call to those who “by NIGHT STAND IN THE HOUSE of the Lord,” to “lift up their hands in the sanctuary and bless the Lord” (Ps. 134), indicating a sunset to full dark Evening Sacrifice service – an impression confirmed by the appointment of Levitical singers for night service in 1 Chron 9:33; 23:30.
The process of the evening sacrifice began in the afternoon but the sacrifice was not offered [burned] until immediately after sunset.
In fact all of the heavy work involved in preparing the evening sacrifice was accomplished BEFORE sunset, except for the actual burning [offering] of the sacrifice immediately when the sun had set. The evening sacrifice is therefore the FIRST sacrifice of the NEW 24 hour sunset to sunset day.
The morning sacrifice was offered [burned] immediately at sunrise, and was the SECOND sacrifice of the 24 hour sunset to sunset day.
The Sadducees [priests] and Jesus Christ did have this correct; and it was the later Rabbinic Hellenizers who either misunderstood or misrepresented the time of the Evening and Morning Daily for their own purposes.
In your research remember that Alfred Edersheim did his research by inquiring into Rabbinic writings and did not study the scriptures.
In any case the Biblical command is clear and it is self evident from the Sabbath ending at sunset that “evening” refers to sunset and not to 3 in the afternoon.
Therefore “Between the Evenings” refers to the period between sunset and full dark [or as many translators put it, at twilight] when the Daily Evening Sacrifice was burned and the Passover was killed.