[BUG] All months start with Sunday after saving configuration

[flyingsquad]

When I click Save Configuration in the Simple Calendar Configuration dialog all the months start with Sunday.

To Reproduce

• Create new world.
• Start it and log in.
• Enable Simple Calendar module
• The calendar correctly displays January 1 as Wednesday (for the current month Jan. 2025).
• Open Simple Calendar Configuration
• Click Save Configuration
• The calendar replots and displays Sunday as the 1st.

This behavior occurs with the Gregorian and all the other calendar types I tried. It also occurs on several different servers that I've set up for testing.

Simple Calendar 2.4.13 works correctly on Foundry 11.315.

Foundry Information

• Foundry Version: 12.331
• Game System: SWADE, FateX, DnD5
• Simple Calendar Version: 2.4.18
• Simple Calendar Configuration: the default calendar when I start

Browser (please complete the following information):

• Browser: Chrome

Is there any way to delete all configuration information for simple calendar? When I disable the module and reenable it, it remembers the previous calendar I had set up. I thought I might have corrupted the setup somehow, so I wanted to start with a clean slate, but I can't figure out how to clear everything after I disable the module.