What do the 5 fields in a cron expression represent?

From left to right: Minute (0-59), Hour (0-23), Day of the Month (1-31), Month of the Year (1-12 or JAN-DEC), and Day of the Week (0-6 where 0 is Sunday or SUN-SAT).

How do step values work in cron (e.g., /15)?

The slash (/) denotes step values. For example, /15 in the minute field means every 15 minutes (:00, :15, :30, :45).

Cron Expression Builder, Visualizer & Humanizer

Visual two-way cron generator, plain-English translator, and next 10 calculated execution timestamps.

Security Guarantee: 100% Client-Side In-Browser Execution. Computations run locally within browser RAM. Zero remote telemetry.

Technical Overview & Architecture

An interactive cron expression builder and humanizer. Translate complex 5-part cron syntax into natural English, select presets for common schedule intervals, and calculate the exact next 10 trigger execution dates and times in your local timezone.

The cron parser parses the 5 whitespace-delimited fields, matching steps (/), ranges (-), and lists (,). It walks forward minute-by-minute from the current system timestamp to discover the upcoming 10 trigger timestamps matching all 5 criteria.

Key Capabilities & Features

Two-Way Interactive Builder: Type any 5-field cron syntax or pick from popular schedule presets (quarter-hourly, daily at 9am, weekly, monthly).
Natural English Translation: Instantly humanizes syntax like */15 9-17 * * 1-5 into "Every 15 minutes, between 09:00 AM and 05:59 PM, Monday through Friday".
Next 10 Scheduled Runs Calculator: Simulates chronologically forward execution to compute the next 10 exact trigger dates and times adjusted to your local browser clock.
5-Part Syntax Cheat Sheet: Visual breakdown showing Minute (0-59), Hour (0-23), Day of Month (1-31), Month (1-12), and Day of Week (0-6).

Step-by-Step Usage Guide

Enter Cron String or Pick Preset: Type your cron expression (e.g. 0 0 * * 0) or select a pre-configured schedule template.
Read Natural English Explanation: Review the human-readable summary to ensure your schedule matches your operational intent.
Verify Next 10 Run Times: Inspect the calculated upcoming execution timestamps to confirm scheduled execution times.

Frequently Asked Questions (FAQ)

What do the 5 fields in a cron expression represent?: From left to right: Minute (0-59), Hour (0-23), Day of the Month (1-31), Month of the Year (1-12 or JAN-DEC), and Day of the Week (0-6 where 0 is Sunday or SUN-SAT).
How do step values work in cron (e.g., */15)?: The slash (/) denotes step values. For example, */15 in the minute field means every 15 minutes (:00, :15, :30, :45).