If it's a regular I would certainly give, and expect, more slack when things go wrong.  On the other hand, if someone's being late is going to interfere with your scheduling for the rest of the day it's probably best to just have them reschedule.  How late is too late? Well, again, that depends on the circumstances.  This is not a "cookie cutter" endeavor that we are involved in and I don't think that there are a lot of "one size fits all" solutions to these issues.

I'm curious...what do you consider proper etiquette for being late? When is it acceptable to still see a client or a provider. If they are 5-15 mins late sure. 30-hour or longer do you reschedule or write them off? Obviously traffic and things happen but I'm just interested in what others consider the right way to go about dealing with this situation.

The world's longest traffic jam... over 60 miles long and lasted 11 days.

When circumstances determine that timing is not working, communication is very important.  

Bills are due ! ........xoxo.

Do we always meet at the exact time?  
Foodguy said it right…
You have to stay in touch..
For me. When meeting for a date..
Not staying in touch is a red flag.
Not only because Im n asshole. And need guidance to find the fucking place.
But I know that girls who have their phone etiquette together are usually much more fun to be with.

Agreed, it's all about communication. I'm going to be far less eager to see a client who was ten minutes late without calling than a client who was thirty minutes late but warned me. It's common courtesy. I'm very rarely late but when I am, I will give an exact ETA if I know it. Don't keep people waiting!

THAT, my friend is the real answer.

delayed by traffic caused by either weather or accident issues. I keep in regular phone contact with the provider if this occurs. Considering I try to be in the immediate area 15-20 minutes before the scheduled date, I have never been more than 20 minutes late.

One Fav & I have had very fluid meeting schedules...  she only provides occasionally & likely I'm the only one she's seeing that day or if she has something else she needs to do.  That said, she blew up on me last visit (I'm no longer as close to her location, so had been a while).  We had both misunderstood the timing...  she did have things to do that day & did not tell me or set a definitive time.  I assumed the same as previous schedule.  And I did call her as per usual when I got on the highway.  The first 20 minutes were taken up by her ballistic rant...  if there had been a way out, I would have...  but it would have proven her point.  We did getto the session but it was definitely off.  

As I've said before, I have to take two days to see a provider in the closest major metro area to me.

I've run my own business for 27 years. I've never been late with a customer. If anything, I've been early, or available early even if they weren't ready. That was drilled into me by those instructors in college who came from the industry.

I couldn't agree more.  Most providers say they expect us hobbyists to be respectful of their time and show up on time and leave when the agreed length of time is up.  Ok, if have the time and she wants to hang out longer that is great.  But I have always tried to be respectful of providers time.  If anything, I usually end up a few mins early and killing time till she is ready.  I would expect the the provider to be respectful of my time as well by being ready on time and not keeping me waiting, often on some street corner looking kind of suspicious..  

Things happen, I know. But just like anyone else she'd be meeting at a specific time, she should call me and let me know she's running late. That's just common respect, and if she can't extend me common respect I don't think we'll get along very well when she does show up.

Have you ever noticed that people who are late are always more jolly than those that are waiting for them

That's the damn truth!!

Normally anything over about fifteen minutes without a call is my cue to bail, but just yesterday I had a lady show up well over a half hour late, the difference was, number one she was supposed to show up at 8 AM, right in the middle of rush hour traffic, and number two, we had an all day date and I had absolutely nothing else planned for the day which we were  both aware of, so in this case the forty minutes or so was no biggie.

On most occasions though, anything more than about 15 minutes without a phone call is unacceptable to me, with a phone call?  Just about anything within reason is ok with me.

Traffic was horrible.  My normal one hour drive to the Incall took me an hour and a half, so I was a half hour late.  She was another half hour late.  We were talking to each other at least every ten minutes.  I knew my trip home was a two hour drive, so it made more sense to wait.  Without the constant communication, I probably would have turned around.

Only because you didn't run out of gas that night.

That can be taken more than one way; however, we both know it was a good thing…

I had a prescheduled date with a Fav lady...   I called when I got on the highway as I always do with her.  It's a long drive but from the call it's about another hour so she can get a good ETA.  Then one time she didn't pick up.  I tried again 10 minutes later.  No pickup.  I got off the road and called another Fav.  I was pretty annoyed though I did have a good time.

no communication.