[Feature] - Forced Themes on specific days

[Paulsenik]

Is your feature request related to a problem? Please describe.
No theme-variations.

Describe the solution you'd like
A theme of a specific type or genre is forced during a specific cake-day or celebration.

Additional context
e.g. A Supermario-theme should be forced on 10. Mar (-> Mar 10)

ideas:

• Pi Day (14. März)
• Mario Day (10. März)
• April Fools (1. April)
• Star Wars Day (04. Mai)
• Minecraft Day (17. Mai)
• Comic Sans Day
• Release of Pong
• Ask a Stupid Question Day
• World Emoji Day
• Ada Lovelace Day
• World Backup Day
• World Standards Day
• International Beer Day
• International Caps Lock Day
• International Coffee Day
• Privacy Day (Data Protection Day)
• System Administrator Appreciation Day
• Birth of the World Wide Web