Calendar Mod

Customizable Calendar System for Minecraft 1.20.1 Forge / Fabric and 26.2 Fabric

Introduction

Calendar Mod is a full-featured calendar mod built on the HtmlCraft API. It introduces a customizable calendar system to Minecraft, where each save has independent calendar data. Players can define era names, month counts, days per month, month names, weekday names, add special date events, and interact through a modern HTML/CSS rendered interface.

Features

Calendar System

Event System

Interface System

Network Sync

Requirements

This mod ships in three versions. Choose the matching version for your loader and Minecraft version.

Forge Version (1.20.1)

Fabric Version (1.20.1)

Fabric Version (26.2)

Installation

Forge Version (1.20.1)

1. Place htmlcraftapi-1.0.0-1.20.1forge.jar, calendarmod-1.0.0-1.20.1forge.jar, and cloth-config-11.x-forge.jar into the mods folder
2. (Optional) Add Catalogue for a config button in the mod list
3. Launch the game

Fabric Version (1.20.1)

1. Install Fabric Loader and ensure Fabric API is present
2. Place htmlcraftapi-1.0.0-1.20.1fabric.jar, calendarmod-1.0.0-1.20.1fabric.jar, and cloth-config-11.x-fabric.jar into the mods folder
3. (Optional) Add ModMenu for a config button in the mod list
4. Launch the game

Fabric Version (26.2)

1. Install Fabric Loader and ensure Fabric API is present
2. Place htmlcraftapi-1.0.0-26.2fabric.jar, calendarmod-1.0.0-26.2fabric.jar, and cloth-config-26.2.155.jar into the mods folder
3. (Optional) Add modmenu-20.0.x.jar for a config button in the mod list
4. Launch the game

Key Bindings

Keys can be customized in Options → Controls → Key Bindings.

Commands

All commands use /calendar as prefix.

Interface Overview

Calendar Main Screen

Press C to open. Includes:

• Header: Era name, year, month navigation
• Weekday Row: Custom weekday names
• Date Grid: CSS Grid layout, today highlighted, dates with events marked
• Events Panel: Shows event list for selected date
• Bottom Buttons:
  • Client Settings: Opens Cloth Config (HUD, styles, etc.)
  • Calendar Settings: Opens calendar config (era, months, etc.)
  • Add Event: Opens event management screen

Event Management Screen

• Date input (year/month/day)
• Event name and description
• Color selection list (12 presets + custom color input)
• Yearly repeat toggle
• Existing events list (supports deletion)

HUD

• Shows current date and weekday
• Shows today's events (configurable)
• Light gray semi-transparent modern UI
• Draggable to reposition
• Position auto-saved to config file

Client Config (Cloth Config)

Style System

Built-in Styles

Adding Custom Styles via Resource Pack

Resource packs only need to provide their own styles.json (containing only new styles) and corresponding CSS files. The mod auto-merges and detects them:

resource_pack/
├── pack.mcmeta
└── assets/calendarmod/templates/
    ├── styles.json              ← Only contains new style entries
    └── styles/
        └── my_style.css         ← Custom CSS file

styles.json format:

{
  "styles": [
    {
      "id": "my_style",
      "name": "My Custom",
      "description": "Resource pack custom style",
      "file": "styles/my_style.css",
      "builtin": false
    }
  ]
}

After enabling the resource pack, open Calendar → Client Settings → Interface Style dropdown to see the new style.

CSS files can use __ROOT_PAD<span style="text-decoration: underline;">, </span>GAP__, and other double-underscore variables, dynamically replaced by Java with screen-adaptive pixel values.

For detailed resource pack creation guide, see Resource Pack Guide.

Resource Pack Generator Tool & Tutorials

The mod provides a GUI-based resource pack generator and detailed tutorials to help you quickly create custom styles:

👉 Tools & Tutorials: docs/

Quick start:

cd docs
pip install -r requirements.txt
python resource_pack_generator.py

Or double-click docs/启动资源包生成器.bat on Windows.

Time System

• Each new save starts from Year 1
• Calendar time is based on actual game time, unaffected by /time command
• Even if other mods reset time, elapsed calendar time never goes backward
• 24000 ticks = 1 day
• Special dates broadcast to all players via ActionBar, once per day

Project Structure

com.calendar.mod
├── CalendarMod.java              // Mod main class, key bindings, network registration
├── calendar/
│   ├── CalendarConfig.java       // Calendar config data model
│   ├── CalendarDate.java         // Date data model
│   ├── CalendarSystem.java       // Calendar system interface
│   ├── ConfigurableCalendar.java // Configurable calendar implementation
│   └── DefaultCalendar.java      // Default calendar implementation
├── client/
│   ├── CalendarClientConfig.java // Client config (Cloth Config)
│   ├── CalendarConfigScreen.java // Calendar config screen
│   ├── CalendarEventScreen.java  // Event management screen
│   ├── CalendarHud.java          // HUD rendering
│   ├── CalendarScreen.java       // Calendar main screen (HTML/CSS)
│   ├── HudRenderSubscriber.java  // HUD render event subscriber
│   └── StyleManager.java         // Style manager
├── command/
│   └── CalendarCommand.java      // /calendar command
├── data/
│   ├── CalendarEvent.java        // Event data model
│   └── CalendarSavedData.java    // Save data persistence
├── network/
│   ├── CalendarClientCache.java  // Client data cache
│   ├── CalendarConfigPacket.java // Calendar config sync packet
│   ├── CalendarEventPacket.java  // Event edit packet
│   └── CalendarSyncPacket.java   // Calendar data sync packet
└── server/
    └── AutoSyncScheduler.java    // Auto sync scheduler

Resource Files

assets/calendarmod/
├── lang/
│   ├── zh_cn.json                // Chinese language file
│   └── en_us.json                // English language file
├── templates/
│   ├── calendar_screen.html      // Calendar screen HTML template
│   ├── calendar_screen.css       // Default CSS style
│   ├── styles.json               // Style metadata
│   └── styles/
│       ├── dark.css              // Dark
│       ├── ocean.css             // Ocean
│       ├── forest.css            // Forest
│       ├── mystic.css            // Mystic
│       └── minimal.css           // Minimal
└── icon.png                      // Mod icon

Addon Development

The mod provides CalendarSystem interface and CalendarSavedData API. Addon mods can:

• Implement custom calendar systems (implement CalendarSystem interface)
• Read/modify save calendar data (via CalendarSavedData.get(level))
• Listen for date change events
• Register custom event types

License

LGPL-2.1

Author

Yifei

Dependencies

• HtmlCraft API — HTML/CSS Rendering Engine