Wanneer begint de dag

http://www.isawthelightministries.com/daystarts.html
https://judaism.stackexchange.com/questions/69630/how-to-reconcile-if-when-the-jewish-day-was-to-begin-at-sunset
https://judaism.stackexchange.com/questions/47635/is-there-really-evidence-that-the-rabbis-changed-the-days-beginning-from-sunris
https://thetorah.com/does-a-day-begin-in-the-evening/
https://70weeks.net/passover/the-day-starts-at-sunrise/
https://bijbeloptiek.weebly.com/bijbelse-definitie-van-avond.html
https://davidwilber.com/articles/when-a-biblical-day-begins-and-ends
https://www.clearbibleanswers.org/books-michael-pedrin/lunar-sabbath-the-big-lie/98-when-does-a-day-begin-lunar-sabbath.html

Nieuwe Testament Grieks

http://www.isawthelightministries.com/resurrectiontime.html

G3796 opse, ὀψέ late

From the same as opiso (through the idea of backwardness);
(adverbially) late in the day;
by extension, after the close of the day -- (at) even, in the end.

G3798 opsios, ὄψιος, ὀψία, ὀψιον (ὀψέ) evening

From opse; late; feminine (as noun) afternoon (early eve)
or nightfall (later eve) -- even(-ing, (-tide)).

https://pcg.church/articles/273/when-does-your-day-beginz

Joh 19:31: “Therefore, since it was the Preparation Day, that the bodies should not remain on the stake on the Sabbath – for that Sabbath was a high one – the Y'hudim asked Pilate to have their legs broken, and that they be taken away.”

An account in Acts can also be used to clarify the beginning of the day. “And upon the first day of the week, when the disciples came together to break bread, Paul preached unto them, ready to depart on the morrow; and continued his speech until midnight. And there were many lights in the upper chamber, where they were gathered together” (Acts 20:7-8).

Act 27:27 “And when the fourteenth night came, as we were driven up and down in the Adriatic Sea, about midnight the sailors suspected that they were drawing near some land.”

Act 27:33 And when day was about to come , Sha’ul urged them all to take food, saying, 'Today is the fourteenth day you have continued without food, and eaten none at all.'“

Oude Testament

The Day of Atonement
Lev 23:26 וַיְדַבֵּ֥ר H1696 vay·dab·Ber spake יְהוָ֖ה H3068 Yah·weh And the LORD אֶל־ H413 'el- to מֹשֶׁ֥ה H4872 mo·Sheh unto Moses לֵּאמֹֽר׃ H559 le·Mor. saying
Lev 23:27 אַ֡ךְ H389 'ach Also בֶּעָשׂ֣וֹר H6218 be·'a·Sor on the tenth לַחֹדֶשׁ֩ H2320 la·cho·Desh month הַשְּׁבִיעִ֨י H7637 hash·she·vi·'I [day] of this seventh הַזֶּ֜ה H2088 haz·Zeh of this י֧וֹם H3117 Yom [there shall be] a day הַכִּפֻּרִ֣ים H3725 hak·kip·pu·Rim of atonement ה֗וּא H1931 Hu, he מִֽקְרָא־ H4744 mik·ra- convocation קֹ֙דֶשׁ֙ H6944 ko·desh it shall be an holy יִהְיֶ֣ה H1961 yih·Yeh become לָכֶ֔ם H0 la·Chem, וְעִנִּיתֶ֖ם H6031 ve·'in·ni·Tem unto you and ye shall afflict אֶת־ H853 'et- נַפְשֹׁתֵיכֶ֑ם H5315 naf·sho·tei·Chem; your souls וְהִקְרַבְתֶּ֥ם H7126 ve·hik·rav·Tem and offer אִשֶּׁ֖ה H801 'ish·Sheh an offering made by fire לַיהוָֽה׃ H3068 Yah·weh. unto the LORD
Lev 23:28 וְכָל־ H3605 ve·chol any מְלָאכָה֙ H4399 me·la·Chah no work לֹ֣א H3808 lo shall not תַעֲשׂ֔וּ H6213 ta·'a·Su, And ye shall do בְּעֶ֖צֶם H6106 be·'E·tzem in that same הַיּ֣וֹם H3117 hai·Yom day הַזֶּ֑ה H2088 haz·Zeh; this כִּ֣י H3588 ki is a י֤וֹם H3117 Yom for it [is] a day כִּפֻּרִים֙ H3725 kip·pu·Rim of atonement ה֔וּא H1931 Hu, he לְכַפֵּ֣ר H3722 le·chap·Per to make an atonement עֲלֵיכֶ֔ם H5921 'a·lei·Chem, your behalf לִפְנֵ֖י H6440 lif·Nei for you before יְהוָ֥ה H3068 Yah·weh the LORD אֱלֹהֵיכֶֽם׃ H430 'e·lo·hei·Chem your God
Lev 23:29 כִּ֤י H3588 ki If כָל־ H3605 chol is any הַנֶּ֙פֶשׁ֙ H5315 han·Ne·fesh For whatsoever soul אֲשֶׁ֣ר H834 'a·Sher who לֹֽא־ H3808 lo- will not תְעֻנֶּ֔ה H6031 te·'un·Neh, [it be] that shall not be afflicted בְּעֶ֖צֶם H6106 be·'E·tzem in that same הַיּ֣וֹם H3117 hai·Yom day הַזֶּ֑ה H2088 haz·Zeh; this וְנִכְרְתָ֖ה H3772 ve·nich·re·Tah he shall be cut off מֵֽעַמֶּֽיהָ׃ H5971 Me·'am·Mei·ha. from among his people
Lev 23:30 וְכָל־ H3605 ve·chol any הַנֶּ֗פֶשׁ H5315 han·Ne·fesh, And whatsoever soul אֲשֶׁ֤ר H834 'a·Sher who תַּעֲשֶׂה֙ H6213 ta·'a·Seh [it be] that doeth כָּל־ H3605 kol- any מְלָאכָ֔ה H4399 me·la·Chah, any work בְּעֶ֖צֶם H6106 be·'E·tzem in that same הַיּ֣וֹם H3117 hai·Yom day הַזֶּ֑ה H2088 haz·Zeh; this וְהַֽאֲבַדְתִּ֛י H6 ve·ha·'a·vad·Ti will I destroy אֶת־ H853 'et- הַנֶּ֥פֶשׁ H5315 han·Ne·fesh the same soul הַהִ֖וא H1931 ha·Hiv he מִקֶּ֥רֶב H7130 mik·Ke·rev from among עַמָּֽהּ׃ H5971 'am·Mah. his people
Lev 23:31 כָּל־ H3605 kol- all מְלָאכָ֖ה H4399 me·la·Chah no manner of work לֹ֣א H3808 lo not תַעֲשׂ֑וּ H6213 ta·'a·Su; Ye shall do חֻקַּ֤ת H2708 chuk·Kat [it shall be] a statute עוֹלָם֙ H5769 o·Lam for ever לְדֹרֹ֣תֵיכֶ֔ם H1755 le·do·Ro·tei·Chem, throughout your generations בְּכֹ֖ל H3605 be·Chol all מֹֽשְׁבֹֽתֵיכֶֽם׃ H4186 Mo·she·Vo·tei·Chem. in all your dwellings
Lev 23:32 שַׁבַּ֨ת H7676 shab·Bat It [shall be] unto you a sabbath שַׁבָּת֥וֹן H7677 shab·ba·Ton of rest הוּא֙ H1931 hu he לָכֶ֔ם H0 la·Chem, וְעִנִּיתֶ֖ם H6031 ve·'in·ni·Tem and ye shall afflict אֶת־ H853 'et- נַפְשֹׁתֵיכֶ֑ם H5315 naf·sho·tei·Chem; your souls בְּתִשְׁעָ֤ה H8672 be·tish·'Ah in the ninth לַחֹ֙דֶשׁ֙ H2320 la·Cho·desh [day] of the month בָּעֶ֔רֶב H6153 ba·'E·rev, at even מֵעֶ֣רֶב H6153 me·'E·rev from even עַד־ H5704 'ad- until עֶ֔רֶב H6153 'E·rev, unto even תִּשְׁבְּת֖וּ H7673 tish·be·Tu shall ye celebrate שַׁבַּתְּכֶֽם׃ H7676 shab·bat·te·Chem. your sabbath פPeh

https://pcg.church/articles/273/when-does-your-day-begin

Psa 55:10 יוֹמָ֤ם H3119 yo·Mam Day וָלַ֗יְלָה H3915 va·Lay·lah, and night יְסוֹבְבֻ֥הָ H5437 ye·sov·Vu·ha they go about עַל־ H5921 'al- her upon חוֹמֹתֶ֑יהָ H2346 cho·mo·Tei·ha; it upon the walls וְאָ֖וֶן H205 ve·'A·ven thereof mischief וְעָמָ֣ל H5999 ve·'a·Mal also and sorrow בְּקִרְבָּֽהּ׃ H7130 be·kir·Bah. [are] in the midst

Psa 55:17 עֶ֤רֶב H6153 'E·rev Evening וָבֹ֣קֶר H1242 va·Vo·ker and morning וְ֭צָהֳרַיִם H6672 Ve·tzo·ho·ra·yim and at noon אָשִׂ֣יחָה H7878 'a·Si·chah will I pray וְאֶהֱמֶ֑ה H1993 ve·'e·he·Meh; and cry aloud וַיִּשְׁמַ֥ע H8085 vai·yish·Ma' and he shall hear קוֹלִֽי׃ H6963 ko·Li. my voice

King David sets us an example of prayer in Psalm 55:17, but not only that—he recognized when the day begins: “Evening, and morning, and at noon, will I pray ….”

Neh 13:15-21: “In those days I saw in Y'hudah those treading wine presses on the Sabbath, and bringing in sheaves, and loading donkeys with wine, grapes, and figs, and all kinds of burdens, which they brought into Yerushalayim on the Sabbath day. So I warned them on the day they sold food. And men of Tsor dwelt there, bringing in fish and all kinds of goods, and sold them on the Sabbath to the children of Y'hudah, and in Yerushalayim. Then I contended with the nobles of Y'hudah, and said to them, ‘What evil matter is this that you are doing, profaning the Sabbath day? Did not your fathers do the same so that our Elohim brought all this evil on us and on this city? Yet you bring added wrath on Yisrael by profaning the Sabbath.’ And it came to be, at the gates of Yerushalayim, as it began to be dark before the Sabbath, that I commanded the gates to be shut, and commanded that they should not be opened till after the Sabbath.

14 En hij zeide tot mij: Tweeduizend driehonderd avonden en morgens; dan zal het heiligdom in rechten hersteld worden.
26 En het gezicht van de avonden en de morgens, waarvan gesproken werd, dat is waarheid. Gij nu, houd het gezicht verborgen, want het ziet op een verre toekomst.

Letterlijk staat er:

En het visioen van de avond (erev) en de morgen (boqer) waarover gesproken hij is waar,
en jij houdt het visioen gesloten voor dagen (yamim) vele (rabim).

This same phrase of “the evening and the morning” is used also in the book of Daniel and is clearly a twenty-four-hour period of time. This is the only other place, apart from Genesis 1, where the phrase “the evening and the morning” is used:

And the vision of the evening and the morning which was told is true: wherefore shut thou up the vision; for it shall be for many days. (Daniel 8:26)

How many days are “the evening and the morning” of Daniel?

And he said unto me, Unto two thousand and three hundred days; then shall the sanctuary be cleansed. (Daniel 8:14)

The Hebrew words translated days in Daniel 8:14 are the same words in the Hebrew of Daniel 8:26, where it is translated as “evening” and “morning.” The Hebrew words are ereb and boqer which are the exact words used in Genesis 1 for “evening” and “morning.”