Chronomate was developed for a small guild I admin. For seasonal events I would switch the icon for a themed one to match the occasion. Chronomate allows you to automate this by setting up tasks on a calendar date.
With Chronomate you can:
📦 Store icon images in a Discord channel for easy access.
🦾 Change the guild icon at any time manually using slash commands.
📆 Setup automatic icon changes.
🗺️ Set the timezone for your server so icon changes will happen 2AM local time.
Take a look at the documentation for more info info on how to use.