Chrono — Task Scheduler Plugin

A Paper plugin for scheduling commands to run on a timer or cron schedule.

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Requirements

• Java 21+
• Paper 1.21.4+
• Maven 3.8+ (to build)

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Build

mvn package

Output: target/Chrono-1.0.0.jar
Copy it to your server's plugins/ folder.

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Commands

/chrono add <schedule> <command> [name:X] [world:X]
/chrono list
/chrono info <id>
/chrono remove <id>
/chrono enable <id>
/chrono disable <id>
/chrono run <id>
/chrono edit <id> <field> <value>
/chrono logs <id> [limit]
/chrono gui
/chrono export [filename]
/chrono import <filename>
/chrono reload

Edit fields: name, command, schedule, world

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Examples

# Announce the server restart in 1 hour
/chrono add 1h broadcast &eServer restart in 1 hour name:RestartWarn

# Save the world every 10 minutes
/chrono add */10 * * * * save-all name:AutoSave

# Clear lag once at a set time
/chrono add once:2025-07-01T03:00 lagg clear name:ScheduledLagg

# Run only in the nether
/chrono add 5m broadcast &4Nether is dangerous! name:NetherWarn world:world_nether

# Manual test run
/chrono run a1b2c3d4

# Disable without deleting
/chrono disable a1b2c3d4

# Export all tasks
/chrono export backup.yml

# Import from file
/chrono import backup.yml

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Permissions

Node	Description	Default
chrono.admin	Full access	op
chrono.add	Add tasks	op
chrono.remove	Remove tasks	op
chrono.edit	Edit tasks	op
chrono.enable	Enable tasks	op
chrono.disable	Disable tasks	op
chrono.run	Manually run tasks	op
chrono.list	List/view tasks	op
chrono.reload	Reload plugin	op
chrono.gui	Open GUI	op
chrono.export	Export tasks	op
chrono.import	Import tasks	op

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Config (plugins/Chrono/config.yml)

timezone: "UTC"          # Any valid Java ZoneId, e.g. "Europe/Berlin"

logging:
  enabled: true
  max-lines: 1000        # Max log entries stored in DB

gui:
  enabled: true
  rows: 6                # GUI rows (1-6)

messages:
  prefix: "&8[&6Chrono&8] &r"

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Data

• Tasks are stored in plugins/Chrono/chrono.db (SQLite)
• Tasks survive restarts automatically
• Export/import uses YAML in the plugins/Chrono/ folder

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Architecture

dev.chrono/
├── ChronoPlugin.java          — Entry point
├── model/
│   ├── ChronoTask.java        — Task data model
│   └── TaskLog.java           — Log entry model
├── manager/
│   └── TaskManager.java       — CRUD, execution logic
├── scheduler/
│   └── ChronoScheduler.java   — 1-second tick loop
├── storage/
│   └── SQLiteStorage.java     — Persistence layer
├── command/
│   └── ChronoCommand.java     — All subcommands + tab completion
├── gui/
│   ├── TaskListGui.java       — Inventory GUI
│   └── GuiListener.java       — Click handler
├── permission/
│   └── Perms.java             — Permission constants
└── util/
    ├── Lang.java              — Messages + MiniMessage
    ├── ScheduleParser.java    — Cron/interval/once parser
    └── ImportExport.java      — YAML import/export