I'm sure it's not a national holiday, but it was a day of celebration for me that both started and ended with secondary swarms.
I was still in my pjs when I got a call from a beekeeper who belongs to my local club, Metro Atlanta Beekeepers. She has two hives and no extra equipment and her hive had swarmed. She asked if I would like the swarm. I was THRILLED to go and get it; threw on my clothes and was out the door. Like most beekeepers at this time of year, my swarm collection gear is always in my car so I can literally jump in and head out, as long as I have put on my own clothes!
She had made a split from her largest hive and there was good evidence that it had swarmed as well. Then a few days later she sees this little teardrop of bees in the tree above her hives: