ditto
I should have specified U.S. on this. I do understand that other cultures do things differently.
I’ve certainly heard “fashionably late,” but always in the context of showing up late to “make an appearance.” I was raised that being late is a not-so-subtle way of telling someone that your time is more important than theirs, and I’ve never understood the concept of giving a time for an event if people aren’t going to pay attention. I do have gatherings where I’ll say, just come over after work, or come by anytime Sunday afternoon. But if there’s a time given, people are planning around it.
I remember a college friend that was perennially late (and I’m talking hours late). A big group of us was going to meet at my place on Saturday morning, and then all drive to another town for the day. We had a bunch of activities planned. Half an hour after the designated time, he still wasn’t there and hadn’t called, so we left without him. He was pissed, but at least he put a little effort into being on time with us after that.
When I plan a dinner party, I plan dinner for around 1.5 hours after the start time. Appetizers are out and hot at the start time. Being 15 minutes late isn’t such a big deal, but 30 minutes is starting to be one because I want the appetizers to be hot and the shrimp fresh, etc. If you’re looking like you’ll be delayed 1/2 hour, I’d appreciate a phone call so I could delay that what could be delayed.
If you bring wine, that’s great. If you don’t, I don’t really care. As hostess, I’ve already bought the wine. I’d appreciate your attendance more than I’d appreciate another bottle of wine and a tardy guest who has thrown off the timing by 30 minutes.
Call and tell them I’m late, start dinner without me. I’ll still be there to visit.
It’s rude not to call, so I’d for sure call. If, when I call, my friend says, “Hey, we weren’t planning dinner for right away anyway. We were planning it for (half hour later or more)”, I’d swing buy the store and buy a bottle. Otherwise, I’d hustle.
If my friends Karen and Lameh are hosting a dinner, I would definitely call (and bring something extra) because, even at 15 minutes late, Karen has turned the oven down to ‘warm’ so the chicken doesn’t over-cook.
Whereas my friends Mel and Eric serve appetizers for two hours and then maybe fire up the grill to throw some 'dogs and burgers on. So for them, 15 minutes late, 30 minutes late, doesn’t much matter.
As a reference, my friend Mel once served a “kitty litter cake”, which was basically uncooked cake batter, mixed with fruit juices, jumbled to look like kitty litter. Then you warm up Tootsie Rolls (by rolling them between your palms) and insert them in the ‘kitty litter’; serve the whole mess in a (new) kitty litter pan, with a (new) kitty litter scoop to dish it up. . .
Karen would faint at the very idea!
So, a lot of it depends on the friend and how formal they are.
I was raised with a rigid midwestern when-it’s-scheduled-@-six-by-gracious-we-mean-it mentality. It’s taken years to recover. 
As a single person, when I’m entertaining, there are always appetizers and drinks going on before the meal. My home is small enough that all of the public areas are in view of the kitchen, so I visit while finishing up the meal. That said, if you’re going to be more than half an hour late, please call so I know how to plan accordingly.
The bottle, chocolates or flowers are appreciated, but not necessary. I’ve invited you, presumably because I like your company.
Just my $.02.
I’d call to say I’m running late, and grab a bottle from the stock in the house. We never have an empty wine rack, so there’s no need for that side-trip because we’re always prepared!
Given the OP says that he has not been to the venue before, it’s safe to assume he can’t tell whether or not the host has everything planned to a meticulous schedule or not. This being the case, a call is compulsory (with profuse apologies), and there is no reason not to do so.
Now that that’s sorted, I first thought that giving the host the option seems like a good solution, but on second thoughts I think it’s actually the worst option. It’s making your problem a problem for the host, and that’s not really fair - if they suggest you get the bottle (and I agree that it is rude to show up without one), they sound like that’s more important than your company (even if they don’t mean to), and if they suggest you don’t, they sound like a control freak who needs you to be there right away (even if that’s not actually the case). So my answer to the poll was to call, and be 15 minutes late with no bottle. You can then arrive not-too-late and explain when you do so why you are empty-handed. However, I would add that you should arrange to send some sort of gift after the event instead.
On the subject of arriving on time - as someone who is always late (whether hosting or visiting), I think arriving at exactly the time specified can be a little annoying - 5 minutes late is ideal. 15 or 30 is too many (if it can be avoided).
Short version: always call, but being without a gift is less rude than being late.
In New Zealand we always bring a botltle of wine with us. Its just taken for granted. If someones nice enough to cook you a dinner, the least you can do is bring some refreshments. When my kids were younger I’d bring some juice or fizzy for them as well. Other than dining at my parents’ I can’t remember the last time I went to a formal dinner. Usually its a bbq - & if someones late, thats their problem.
I’d call & say I’m running late cause I’m a punctuality freak. But a lot of people over here aren’t.
Being late for dinner is unforgivably rude. If you know an hour ahead of time you’re going to be late, call and cancel, apologize profusely and let the host know you’d be open to doing it another time if they’ll have you.
I voted to call and say I’d be 30 minutes late (and I’d have a bottle).
Even if I was only going to be 15 minutes late, I’d still call. I think the cutoff is somewhere between 5 and 10 minutes. Any earlier and I’d just show, after that, I’d call.
At our place, dinner is usually planned for 30 minutes after the invitation time, so it might be put as 6:30 for 7. That means you can turn up from 6:30 and dinner will probably be on the table at 7. Even so, if you aren’t going to be there within 5-10 minutes of 6:30, call.
Typically, people tell you what time they plan to eat, and what time they would like you to be there. The latter is usually an hour or so before the former, sometimes longer. How big a deal lateness for the pre-dinner social time is depends a lot on how big a proportion of that period you’re going to miss. If you’re going to miss more than, say, a quarter of that time, or you will be more than an hour later than you were told to come, whichever time is shorter, you need to call.
Of course, I’m still boggled at the notion of a good friend whose whose home I’ve never visited.
Am I the only one who finds the whole idea of needing to bring something odd? To me it comes off as incredibly insulting, as if saying “I don’t trust you to provide enough for us, so I’m going to have bring something of my own.”
It just seems to me if you’re the uptight type that has everything planned down to a T that I have to worry about telling you if things don’t go exactly as planned, you’re not going to want me adding something to the plans you’ve already made.
The more I hear about these differences, the more I think these social customs are not conducive the concept of friendship and civility. All it takes if for one person not to know one of the rules, and you’ve just created pointless conflict. Neither intended to hurt the other, but both are going to wind up hurt.
I think we as a people should start telling people what we expect of them, instead of assuming that the other person knows what’s going on in our head.
Now, to answer the question: I’d call, probably, as the question seems to assume that being late is a problem, and that I know this. Therefore I would be remiss to call. But, in real life, it entirely depends on the person.
And I would never bring a bottle because, even if a gift is expected, I would find it rude to bring something and then be unable to actually share it, as I myself cannot drink.
Well, its different customs in different countries. My husband didn’t drink for a while & when I was pregnant I didn’t drink. I can’t remember what we brought then.
I know as a hostess I would always appreciate flowers.
That’s not what the bottles are about–and it doesn’t have to be a bottle, although it’s usually food or drink related. It’s just fine to bring a “hostess gift” and say, “here’s something I really enjoyed–I though you might want to give it a try sometime.” It doesn’t have to be consumed that night.
The bottle really wasn’t intended to be the main part of the question (except in that it causes a delay). The “social custom” I was speaking of is really simple and easy: if you accept a dinner invitation for 7:00, you show up at 7:00.