My brother and I had an interesting discussion about times of day. Specifically, when the arbitrary destinctions of “morning,” “afternoon,” “evening,” and “night” are.
Here’s my take.
“Morning” is from 4:00 to 12:00
“Afternoon” is 12:00 to 6:00
“Evening” is from 6:00 to 11:00
“Night” is from 11:00 to 4:00
What’s your take?
Why?
Anytime I have to get up before 5 am is just an ungodly hour.
Noon is self-explanatory.
People typically get out of work around 5, but I feel that the time spent running around before dinner/supper/whatever-you-call-it is still afternoon.
When I lived with my parents, if you were up into the 10 pm news broadcast, you were up late. So that’s been imprinted on me as the cutoff time.
None of this applies to me personally, of course. I’m self-employed, so I don’t punch a clock. Mr. S is working some goofy rotating night-shift thing, and we’ve both worked odd shifts on and off. No kids, so we have no set feeding schedules. So these days my schedule is more like this (on Mr. S’s working days):
Morning: 8:15, when he gets home from work; he goes to bed around 9 and I work until he gets up, around 3 or 4
Afternoon: noon
Evening: 5:45, when he goes to work and I hit the salt mines again
Oh, and when the phone rings after 9 pm, it better be a close friend or family member with a terrible problem. You just don’t call people after 9 pm (except by prearrangement). My mom brainwashed me good, by golly.
I remember reading that the day was divided thus in old New England:
morning: 4 A.M.-8 A.M.
forenoon: 8 A.M.-noon
afternoon: noon-4 P.M.
evening: 4 P.M.-8 P.M.
night: 8 P.M.-4 A.M.
I don’t know anybody who uses the word “forenoon” any more, but my great-grandfather used it many times in his diary (circa 1915). He was a dairy farmer from New Hamsphire who was born in the late 1850s.
Crack of dawn: 4:00am - 6:00am
Morning: 6:30 - 10.30
Mid-morning: 10:00 - 11:30
Midday: 11:30 - 12:30
Lunchtime: 12:00 - 2:30
Early afternoon: 2:00 - 3:00
Mid afternoon: 3:00 - 4:00
Late afternoon: 4:30 - 5:30
Early evening: 5:00 - 6:30
Evening: 6:30 - 9.00
Night: 9.30: - 12:30
Early hours: 1:00 - 5:00
Some sort of overlap though.
12:01 am - 5:59 am ungodly hours of morning
6:am - 11:59 am morning
12 noon
12:01pm - 5:59 pm afternoon
6:pm-8:59 pm evening
9:pm- 11:59 pm widely scattered dark night
12 midnight
smilies provided by winken the wonderful.
she has a fast right paw.
Morning = 6:01 - 12:00
Afternoon = 12:01 - 18:00
Evening = 18:01 - 24:00
Night = 00:01 - 6:00
Sure, rocking chair, blame it on the cat. We know better. 
Morning, evening, and so forth - these are variable concepts, in my limited experience. Sometimes the times associated with the terms overlap; sometimes not.
In temperate latitudes, evening begins at 6pm or when darkness falls, whichever is earlier. So in the winter, “5-o’clock in the evening” exists; in the summer, it doesn’t. But “6-o’clock in the afternoon” sounds wrong at any time of year, even if you have another three hours of daylight to go.
You can say both “10-o’clock in the evening” and “7-o’clock at night”, and not be wrong, even if it’s more comfortable the other way around.
Or so it seems to me. This is definitely YMMV territory.
For me, it all runs on a scale, overlapping depending on perspective (a sort of half-empty/half-full thing).
For example, evening begins and afternoon ends between 5 and 7 pm. As the clock progresses between that time, it becomes less afternoonish and more eveningish. For example, at 5:30, I’d say the split was 10% evening, 90% afternoon. At 6:45, it’s more like 90% evening, 10% afternoon. Make sense?
When I make the arbitrary jump from calling it one thing versus another depends largely on mood, level of energy, amount of daylight, weather, how long since my last meal, etc.