I disagree. I can’t remember having ever seen calendars display any day other than Sunday as the first of the week, except in the case of computer software made by non-Americans who didn’t think to localize it.
Edit: also on a Friday, you can say next week and mean Monday (3 days later)
I was always under the impression that Americans basically agreed on that the week started on Monday, that the weekend ended with Sunday and that next week meant after Sunday. I thought Sunday as the first day in American calendars was a "yeah, it's stupid we do it like that, but I guess that is how it used to be back in the days" kind of thing.
The week starts on Sunday. The weekend ends on Sunday. It only makes sense if you consider two adjoining endpoints of previous weeks to be one "weekend", which I've never known anyone not to do without thinking about it.
Someone talking at work might mean something different, but I don't usually hear "next week" to mean Monday-Sunday in general conversation and we'd probably clarify for Sunday anyway.
If someone says "The week of the 15th" and Sunday is the 15th, they mean the seven days from 15-21 not the seven days of 9-15.
"Next week, maybe Sunday" means the next calendar Sunday as in Sunday-Saturday, not the Sunday after that as in Monday-Sunday.
Anyone who says otherwise is selling calendars with a Monday start of the week. :)
If I say "next Wednesday" on Thursday, I mean the Wednesday of next week, not "this Wednesday" which was yesterday.
"Next Weekday" of a weekday that's yet to happen, means one week after that day within this week.
"Next Weekday" of a weekday that already happened, means the very next instance of that day in the calendar, "This Weekday" refers to the past.
"Hey, this Tuesday was your presentation right? How did it go?"
"We rescheduled for next Monday actually". <- this is obviously the Monday after the coming weekend.
But even with people I don't put in that category, I'd hesitate to assume +13 days if they said "next Sunday" on Monday. More likely they mean +6 when it's so far out...
Interesting to see so many people here who do interpret it that way.
For example, when driving, to her "turn at the next corner" means "the corner after the next", while to me it means "the corner the car is about to cross". What I call "the next corner" to her is "this corner".
Same with days, of course.
It drives me crazy!
“Next week” on a Sunday is ambiguous because some people consider the new week to have started while others consider it to start the next day.
Likewise, on a Friday afternoon most people (in my experience) don't say "Hey we're having a cook out next Sunday, want to come?" and mean the Sunday in exactly two days. Again, because the phrase "this Sunday" is available and more precise.
In fact, I think in my experience "next X" almost always implies a full 7 days between now and the X. If my boss on Monday says "we need this in production next Friday" I don't normally take that to mean "we need this in production in the next 4 days.
It's the case of saying "next Tuesday" on a Thursday, and meaning that no Tuesdays will pass before the date in question, versus saying "next Thursday" on a Tuesday, where a Thursday will happen before the date.
That's because on Thursday, "this Tuesday" has already happened. But sometimes people will be thinking of "Tuesday after next" when they say "next Tuesday" on a Thursday, because they mean "the Tuesday after the coming Tuesday" and not "the Tuesday of next week".
Since “next Tuesday” also puts the sentence context into the future, the ambiguity exists around whether it means “Tuesday in 5 days” or “Tuesday in 12 days”
If no such ambiguity existed, we wouldn’t need common phrases like “this coming Tuesday” which clarifies the speaker is talking about the “next Tuesday with no other Tuesday’s in between”
Amusingly I don’t think there’s much ambiguity around “the Tuesday after next” as a phrase even though it should be equally ambiguous, but I’ve never heard that phrase to mean “3 Tuesdays from now”
But when communicating with other people, it matters what they understand. And I've come across enough people who don't use "next Monday" like that to understand the word "next" means trouble.