The hive swarmed!
I did not see it, but they left June 26, 2019. Could easily see only half the population, and at least one queen cell along the window. Wish I would have seen the swarm. Now, for the timing: Queen cells should have been just capped. Timeline: Swarm, day 1 +7-14 days for virgin queen to emerge +21 days (1 week to mate, 1 week to start laying, 1 week until first new brood is capped) 28-36 days after swarm new brood capped, 40-48 days after swarm new brood emerge.