Cron Expression MCP Server

Cron Expression

Work with cron scheduling expressions: parse them into human-readable descriptions, validate syntax, show upcoming execution times, and generate expressions from natural language descriptions.

Capabilities

• Explain: Convert a cron expression into plain English (e.g. "0 9 * * 1-5" → "At 09:00 on every day-of-week from Monday through Friday").
• Validate: Check if a cron expression is syntactically valid and report specific field errors.
• Next runs: Calculate the next N execution times from a given cron expression and reference date.
• Generate: Convert a natural language schedule description into a cron expression.

Cron Format

Standard 5-field: minute hour day-of-month month day-of-week

Gotchas

• Day-of-week numbering: 0 = Sunday in standard cron. Some systems use 7 for Sunday.
• Both day fields: Setting both day-of-month and day-of-week creates an OR condition (runs if either matches), not AND.
• @reboot, @yearly, etc.: Shorthand expressions are expanded to their 5-field equivalents.