at (time): 時の臀??点、何時、何分、正午、真夜中な縺?
on (day): 特藹??の日、何曜日、何日の午前/午後な縺?
in (season/month/year): 比較的長い期間、月、四季、年な縺?

at 9:00, at one oclock, at dawn, at sunset, at noon, at midnight, at Christmas
on Saturday, on May 6, on the weekend, on Christmas day
in April, in 2007, in April 2019, in the 21st century

日臀??ま縺? on、月だけ in
on March 2
in March

1日縺?on : on my birthday/Friday/Christmas day/May 25等
2日以上縺?in : in the month/the past week/winter等

詳し縺?
曜日・日臀??・時間・場所でバリエーショ繝?
at six in the morning of 20 April
at 4:00 pm on Friday, 12 February 2010
on Wednesday, August 13, 2:00-3:00
on Wednesday, Jan. 18, at the Moultonborough Library at 7 p.m.
at 5:00 p.m. on Saturday, December 10, 2016
at 5.00 p.m. on Saturday 10 December 2016
Saturday, April 28, 2018
Friday, May 4 2018, 4:00 pm, Yoyogi Park
on Friday, May 5 2018, at 9:00 am in the conference room
https://bebeblanchecoco.com/date-time-location/
書く：一般的には「時刻、曜日、月、日、年」または「曜日、月、日、年、時刻」
March 28, 2012 at 07:03 PM EDT
29 March 2012 at 10:40
March 28, 2012, 11:28 p.m. ET
Thursday 29 March 2012 06.43 EDT
10:57AM BST 29 Mar 2012
https://english-columns.weblio.jp/?p=439

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in the morning
なぜin the morningなのか、広がりのある時間帯をさすことばだから[中縺?]縺?inを藹??る

特別な日、修飾する語が付縺?と限定的になりinからonに・??新聞等で縺?onが省略されることもある）
on Monday morning
on the afternoon he has born
on the morning of April 28
on the morning of his departure
on a cold morning

しかしこの場合縺?inのまま・??主臀??が朝だから）
in the fresh of the morning
early in the morning

しかしこれ縺?on（主臀??が朝でも限定されているから）
by 10 am on the morning of February 25

日時縺?thisやevery等が付縺?場合は副鐔??なので前置鐔??は臀??要
I go to church every Sunday.
I will go to church this morning / tomorrow morning /the following morning.

読みは藹??数でありfirst, second, thirdだが、十の臀??縺?eleventh等なの縺?th
11th, 12th, 13th
21st、22nd、23rd
31st

12時の読みに縺?0ゼロを使繧?ない
twelve noon, twelve midnight, 12AM, 12PM