The banks use “biweekly” and “semiweekly” to avoid this exact kind of ambiguity. Biweekly would be twice a week, while semiweekly would be every other week.
It comes up in banking a lot because of payroll. If you get paid every other week, you get paid semiweekly. But if you get paid on the 1st and 15th of every month, you get paid bimonthly.
Canadian here, with 50 years in the workforce. I've never once been paid semi-weekly or bimonthly. Here, biweekly is every two weeks semi-monthly is every half month. Obviously, that latter is often spoken of as twice a month, which just adds to the confusion between "bi" and "semi".
The reality is that these words, like most words (at least in English), mean whatever the speaker wants them to mean and consensus can be hard to reach.
I give you the phrase "table the discussion". Sometimes it means to formally bring something up for discussion. Other times it means setting the discussion aside for future consideration.
Or, my favourite from my childhood, "fat chance" which means that something is even less likely than if it had a slim chance. Granted, that might be more in the line of idiomatic slang, but it stands as part of at least the era's Canadian English that did have broad consensus and still does, I think.
On the last part: sometimes words drift to be widely accepted as an exact opposite of the original meaning. I think that happens because they were never popular enough for people to remember what they really meant or because too many people used them incorrectly.
An example you gave "fat chances" feels like it was originally sarcastic but then stuck, "quite a bit" feels the same way although I don't know for sure.
And then apparently there are also contronyms that has exact opposite meaning, so yeah some things just require more explanation 😅
That seems backwards to me. Mainly because if you move it to years instead of weeks, something that happens twice a year happens in half a year (semiannual) while something that happens every other year happens in 2 years (biannual).
Of course, I guess you you argue that it isn't much time for the thing to happen, but how many times it does happen. The shareholders meeting happens in January and July, so it happens twice in a year, and it should be semiannual. This is because it happens is semi-year, or 6 months. But you could argue that it happens twice in a year, so has bi-annually.
I realized I may have talked out of my original point, but I feel like my initial comment (semiannual is 6 months, and biannual is 24 months) is easier to understand.
Yeah. That makes no sense. While it seems the bi- prefix is ambiguous, semi- means "half". I don't see how semiweekly can possibility mean every other week.
I hate the fact that you can't correct people on language once a critical mass of misunderstanding happens and the dictionary codifies it. I get that is how dictionaries work, but it doesn't mean I have to accept people saying biweekly to mean semiweekly. We have two words for two concepts, and we're losing that.
If semi means half, then semi-weekly means half weekly. The problem is that this is still ambiguous, as you can interpret it as half the time span, so twice a week, or half the frequency, so ones every 2 weeks.
I know there is a difference in how people perceive time and I feel like this has something to do with that, but I can't quite put it to words
I get it can be confusing. We all have little mental quirks that sometimes make us feel like most people get something we don't. Eg, one of mine is that I can't get used to a digital watch. I like the more graphical format of an analog dial.
I just wish people would consult a dictionary a little more often than they do. Instead, it seems like they hope to confuse enough people to change the dictionary.
I'm just saying that whenever someone says "biweekly", it is now incumbent on me to ask, "do you mean fortnightly or semiweekly?". It slows down communication for no real benefit.
I do sometimes say "fortnightly", but as I already have a Backpfeifengesicht, I try to avoid it.
I've never heard of the concept of being paid twice a week, unless if you get paid daily but only worked twice that week. Is that really a thing in payroll, because I've only heard of biweekly pay to mean once every two weeks.
Semiweekly isn't a term I've ever heard, but I've never worked at a bank.