At Night or In the Night? - English Language & Usage Stack Exchange
1. The origin of "at night" to indicate a point of time and the usage of prepositions "in" and"at" In olden times, when the time expression "at night" was originated, night might have been thought as a point of time in the day because there wasn't any activity going on and people were sleeping that time unlike daytime.

word usage - 1 o'clock in the morning OR 1 o'clock at night? - English ...
4 Morning means after I wake up. Night means after I go to bed. 1 o'clock in the morning means you've woken me up so knock off that damn racket. 1 o'clock at night means I've have fun staying up late so stop complaining about the racket I'm making. So yes they both mean 1 am. The way we talk about time has a lot to do with how we feel about it.

What's the difference between “by night” and “at night”?
The expression by night is typically used to contrast someone's nighttime activities to their daytime activities, especially when the nighttime activities are unusual or unexpected.

Evening and night in English - English Language & Usage Stack Exchange
How exactly are the words 'evening' and 'night' used in English? Are there certain times when evening, and when night, are considered to begin? Do these periods overlap?

What is an appropriate greeting to use at night time?
“Good night” or “good evening”? I am in the process of creating a software application which displays a greeting to users based on the time of day. I have come to a blank on what to display to the user when it is late at night. 'Good night, [user's name]' just doesn't seem right. So, what is an appropriate greeting to use at night time?

word choice - Is "yesterday night" acceptable? - English Language ...
1 "Last night" is more specific but I don't think anyone would object to calling "tonight" part of "today." (At night) What did you do today? (At night) What day is it today? However, you certainly wouldn't say "today night" instead of "tonight." I checked my local dictionary for a definition of "yesterday": the day before today.

Late Night vs Early Morning [duplicate] - English Language & Usage ...
Can anyone explain me Difference between late night & early morning ? "I slept early morning".Is this sentence correct ? What time is called morning ? After 12:00 AM ?

meaning - How should "midnight on..." be interpreted? - English ...
Friday night at midnight probably will always be interpreted as "Midnight in the night which follows Friday evening". Midnight tonight This means (to me) the midnight following today. 11:59 PM Friday 12:01 AM Saturday These are totally unambiguous.

meaning - Why does "one-night stand" mean sex? - English Language ...
From NOAD: one-night stand noun 1 informal (also one-nighter) a sexual relationship lasting only one night. • a person with whom one has such a relationship. 2 a single performance of a play or show in a particular place. The etymology is from the "play or show" meaning and the word probably comes from "stand" used in the military sense, as a confrontation: • an act of holding one's ground ...

meaning - Is the usage of “night and day” as “completely different ...
Similar to day and night, except it implies an improvement of the situation rather than a deterioration. So my question: Is the usage of ‘night and day” in the meaning of “completely different” popular, or still on the sideline? Because I don’t find it in any of Cambridge / Oxford / Merriam –Webster English Dictinoary.