It was "Queen's Day" here, which is a huge national celebration of the Queen's birthday. Think Mardi Gras, except that everyone was wearing orange, there were no beads and the day began with a mass yard sale, which ended at noon when the drinking began. It was an experience, but I don't really need to repeat it. I'm also really glad I stayed in Ouderkerk rather than going to Amsterdam.
This photo was taken just after noon about 5 houses up from me. As you can see, not so crowded yet:
This one was about 14:00 across the river. Lots of orange, everywhere.
I stopped taking pictures after that, because I don't really need loads of photos of people drinking outside. The highlight was spending a day outside as it was (as you can see) gorgeous.
I enjoyed today, the day after queen's day better. I rode my bike to Uithoorn along the Amstel River (about 10 km) and had a lovely brunch. The return trip was all up-wind, so took a bit longer, but the only people out today are those who are serious about their biking. So hardly any cars or other traffic. Lovely.