In UK Churches, it is common to observe a 2-minute silence at 11am on the Sunday next after 11 November (unless 11 November is a Sunday, when that will do). There is a growing tendency to observe a 2-minute silence at 11am on 11 November whatever day it falls upon (in the University where I work they sound the fire alarm, having pre-announced that they will do so).
As for poppies, they seem to appear earlier and earlier every year. The BBC mandates that presenters wear them from mid-October, which is a bit ridiculous. I used to wear them only on 11 November and the following Sunday, but of late I have switched to small enamel pins which are worn year-round on my coat collar. That's quite separate from putting money in a collecting tin, which of course I do every year.