Upon moving to the central belt, and ingratiating myself into more middle class circles of friends I then discovered:
Breakfast - eaten usually when you get up in the morning, say early morning until ~1030am
Lunch - eaten from 12pm until ~2:30pm
Afternoon Tea - taken from around 3:30pm until 4:30pm (cakes/biscuits [cookies] and would also include some kind of sandwich - often cut into triangles)
Tea - 5pm until 6pm - usually a lighter two course meal (say an omlette) and some pudding (desert).
Dinner - taken from 7pm until perhaps 9pm - this would be a fully laiden two or three course meal.
Supper - taken from around 10pm until around 11pm (or just before bedtime) - likely cheese on toast or crackers & cheese and a cuppa.
Obviously you don't need to have every one of these meals every day of the week.
And there can be other terms of course. In Guadalajara, México, where I live, schools say "hora del lonche" (lunch time) to the midday meal.
Edit: He also says 'cena' is a more formal, less common way to refer to dinner.
Google translate translates lunch first as almuerzo and second as comida if you try it.
And sometimes if you're really lucky you'll meet a Southerner who'll freak out about it, "Ha! You said 'dinner' but you meant 'lunch'!! Ha! Ha! When do you eat your lunch?! Ha Ha!!"
I had an old boss that did this regularly. The dick.
If you have the main meal in the middle of the day then it is called "dinner". The snack you have at the end of the afternoon is "tea".
If you have the main meal at the end of the afternoon it is "dinner". The snack you eat in the middle of the day is "lunch".
The difference probably depends on if you go home for a meal at mid-day or not. The later is probably more traditional as people used to work or study much closer to home. And there was somebody around during the day to prepare a meal. But nowadays going home for a main meal in the middle of the day is unusual so we all just have a small snack.
On the other hand, the after-work evening meal is usually less heavy, and is rendered as "supper" in English. And, again, I find that Americans usually assume that it takes place much later than it normally does, and is also much lighter than it normally is (basically a snack rather than a proper meal), if I use that word.
So clearly there is some implicit time-of-day mapping there.
I was always told that dinner (from "dine") is the main meal of the day. So if you have a 'fancy' afternoon meal that can be your dinner (e.g. we usually do Christmas dinner between 3 and 4).
I wonder if HN knows of a linguistic map for meal names, it appears that these words shift meaning a lot.
EDIT: I thought this was interesting -- "Harvard's Dialect Survey had the question, 'What is the distinction between dinner and supper?' Here's the geographic distribution of their results from 10,661 American respondents" https://english.stackexchange.com/questions/22446/lunch-vs-d...
One other great British-English question is "what do you call an individually portioned baked bread article" ... roll, barm, bap, cob, ...
"Christmas lunch is what most of our readers would eat, not Christmas dinner. Use the latter only if referring specifically to an evening meal."
http://www.telegraph.co.uk/topics/about-us/style-book/143530...
https://books.google.com/ngrams/graph?content=Christmas+lunc...
Also this:
https://trends.google.co.uk/trends/explore?q=Christmas%20lun...
In spanish you have 3 distinct meals, 'desayuno' 'almuerzo' and 'cena' mapping strictly to a moment of the day, more or less 'breakfast' 'lunch' and 'dinner', with the option of a merienda (roughly 'tea' but usually just sweet food like cookies or some such) between lunch and dinner. Each of this happens on a specific moment of the day (morning, noon, the optional afternoon thing and well into nighttime).
Are there other languages/dialects where the word maps the importance of the meal instead of the actual time it is consumed?
At some point dinner transitioned to lunch and teatime to dinner for us.
Dinner is definitely most common near me but I wouldn’t blink if someone asked me over for supper or said it’s supper time.
The three meals are "Breakfast", "Lunch" and "Supper". And if Lunch or Supper is the biggest/most formal meal of the day it may be called "Dinner" instead. Hence family "Christmas Dinner" may be at lunch time, but your "Dinner party" is in the evening.
1. http://www.dictionary.com/browse/supper 2. http://www.dictionary.com/browse/dinner
Interesting side note, Sup (verb) the root word for supper has been in the (old) English language since before 900 AD.
Outside of farming people have their main meal (dinner) when they come home from their office in the evening. So the lighter meal in the afternoon becomes lunch and theres no tea.