Here's a timeline of the quick growth of my first buttercup squash on the plant.
A day or so after it bloomed Three days later A week later
Unfortunately the two other female blossoms that have bloomed since aren't progressing as fast. I was sure they were fertilized, yet they are just about the same size as when they bloomed 3 or 4 days ago. I'm afraid they may have a yellowish tint which may mean they will be dropping off soon.