You could say "yes", as far as most people who are serious to do the formal practice in an intensive way. Ever since the Buddha, I think it even happened in the first or second year of his teaching, they started doing what's known as "rains retreats". For three months of the year, the monks and nuns do not move away from their monastery they stay at, or the retreat centre, or whatever it's called. They stay at that one place, they go to the town for food and they go back to that place. They do not wander. The don't travel from town to town, village to village. For three months each year, that's been going on for 2500 years.
During that time, it's expected that the meditation practice will be worked on more intensively. It won't always be done at every centre, but it's expected. You will find that, in general, even the normal little city Wats will often do something a little special during that three months. As much as the monks here at Wat Kow Tahm are not super meditators, often, during that three month period, they will add chanting morning and evening at the lookout. That's something extra they will do for the three month period. So retreats, in that sense, have been ever since the Buddha was alive.
As to the 10-day retreat, like we run and this type of format, of being very intensive in a short period, as much as I know it began in Burma 60-70 years ago, I'm not sure exactly when. When Burma became a British colony, it took on the practice of having Saturday and Sunday as non-working days, basically you didn't work weekends The Burmese devised this 10-day retreat, which is actually 9 nights and only 8 full days, so that it would start Friday night after work and end the next week on a Sunday before work started again. So they only took one week off work. Very convenient, right? So it was formulated for the Western working week, so that people would only take one week off work.
As to how it's run these days, of course there are many different variations. We like to have this length of time. We think it's very good. Every couple of years we run a 20-day retreat. Next year it'll be a new, special, 19-day retreat. Other centers will run a month retreat, a 3-month retreat, whatever. Sometimes weekend retreats. They even call one day a retreat, even though you don't sleep there, just simply because for that one day, they're going to have total silence shared together and practice more intensely. So this has been developing in the West, as a very good way for a lot of people to jump into the practice, get a lot of information very quick, and see whether they enjoy it or not.