We had a PA announcement at about five minutes to eleven, at work, from the building management office to all of the companies on the various floors of the building. Although I always support the silence, I did think that that was a bit draconian for people who, for whatever reason, did not wish to observe the silence. It would be far better to make one of the larger rooms in the building or the atrium a gathering place for those of us who wish to pay our respects. It's pretty difficult to have a meaningful, respectful silence in an office space, with phones going off across the floor and other people choosing not to observe it.
In the event, I went outside the building and stood on the landscaped forecourt. What surprised me, though, was the number of people wearing poppies that marched in and out of the building, completely ignoring the time!