It's well known that the world was created on the 25th of Elul, but what time of day? Yes it says "and it was evening, and it was morning, one day", implying it was created during the night, but what time at night exactly? Was it at the beginning of shkia, during bein hashamashos, the minute of tzeis (which would depend on if you folow the magen avraham etc), or chatzos halayla?
Are there any midrashim / agada / rishonim on the subject at all?
בְּיוֹם עֲשׂוֹת ה' אֱלֹהִים אֶרֶץ וְשָׁמָיִם, בֵּית שַׁמַּאי וּבֵית הִלֵּל. בֵּית שַׁמַּאי אוֹמְרִים מַחֲשָׁבָה בַּלַּיְלָה וּמַעֲשֶׂה בַּיּוֹם. וּבֵית הִלֵּל אוֹמְרִים מַחֲשָׁבָה וּמַעֲשֶׂה בַּיּוֹם. אָמַר רַבִּי שִׁמְעוֹן בֶּן יוֹחָאי, תָּמֵהַּ אֲנִי אֵיךְ נֶחְלְקוּ אֲבוֹת הָעוֹלָם בֵּית שַׁמַּאי וּבֵית הִלֵּל עַל בְּרִיַּית שָׁמַיִם וָאָרֶץ, אֶלָּא מַחֲשָׁבָה בֵּין בַּיּוֹם בֵּין בַּלַּיְלָה, וּמַעֲשֶׂה עִם דִּמְדוּמֵי חַמָּה.
"On the day the L-rd G-d made Earth and Heaven".
There is a debate between Beit Shammai and Beit Hillel:
Beit Shammai say, "The thought was at night and the deed was during the day." And Beit Hillel say, "The thought and the deed were during the day."
Says R. Shim'on b. Yohai, "I am astounded. How can the fathers of the world, Beit Shammai and Beit Hillel, argue about the creation of Heaven and Earth? Rather, the thought was during both day and night, and the deed was during twilight."
You could try the approach of the Rashbam on verse 5 who seems to say that everything was created at the start of each day. After a full day came the night - and then the start of the second day.
ויהי ערב ויהי בקר - אין כתיב כאן ויהי לילה ויהי יום, אלא ויהי ערב, שהעריב יום ראשון ושיקע האור, ויהי בוקר, בוקרו של לילה, שעלה עמוד השחר, הרי הושלם יום א' מן השישה ימים שאמר הקב"ה בעשרת הדברות, ואח"כ התחיל יום שני, ויאמר אלהים יהי רקיע. ולא בא הכתוב לומר שהערב והבקר יום אחד הם, כי לא הוצרכנו לפרש אלא היאך היו ששה ימים, שהבקיר יום ונגמרה הלילה, הרי נגמר יום אחד והתחיל יום שני.
Or you could take the approach of the Malbim on the chapter of creation - he describes how the verses are describing a natural/scientific evolution.
As each phase was completed, a new day was declared. (At least until the sun was put into orbit at which point it became visible when a day started or ended). This ongoing evolution continued until sunset on the 6th day.
