Since it was around 103 degrees today here in the Land of Oz without a cloud in the sky, I figured that I could really charge up the scale and watch hands. I set one scale directly in the sun along with a Casio watch that I had stored away. Since I wear this Casio watch on occasion, I could roughly estimate glowing times for the Stayglow scale by comparing it to the brightness of the watch hands.
After leaving them outdoors for around an hour or so, I then brought them inside to my improvised darkroom, and tried to take a picture of them every 30 minutes until I felt the camera would not register an image anymore. (My camera was set for f 2.8/4 sec and an ISO of 400.)
Here is the original test target/subjects:

And images roughly every 30 minutes:


One hour


Two Hours


Three Hours


And really being bored today, I made an animated GIF showing a few of the shots above in sequence:
