Cronsultant is a lightweight, interactive cron expression assistant built to help users write, understand, and preview cron jobs in real time. Inspired by crontab.guru, it features a clean, terminal-style UI with support for natural language parsing, upcoming execution previews, syntax highlighting, and interactive learning tools.
Cronsultant helps developers and system administrators:
- Build accurate cron expressions with instant feedback
- Understand what a cron schedule really means in plain English
- Preview upcoming run times across different timezones
- Learn cron syntax interactively with smart templates and challenges
- HTML5
- CSS3 (custom theme with light & dark mode)
- JavaScript (ES6+)
- No frameworks, no build tools — runs purely in the browser with vanilla JS.
- Open the Cronsultant page.
- Enter your cron expression in the main input field (e.g.,
0 9 * * 1). - Cronsultant will:
- Parse the expression
- Show a human-readable description
- Display the next upcoming execution(s)
- Use the timezone selector, copy button, or explore preset templates and lightning challenges.
- Hover your cursor through the input to highlight the corresponding part of the expression in the output.
Cron jobs follow a 5-part schedule format:
* * * * *
│ │ │ │ │
│ │ │ │ └─── Day of Week (0 - 6 or SUN–SAT, where 0 = Sunday)
│ │ │ └───── Month (1 - 12 or JAN–DEC)
│ │ └─────── Day of Month (1 - 31)
│ └───────── Hour (0 - 23)
└─────────── Minute (0 - 59)
Each field controls a specific unit of time:
| Field | Position | Allowed Values | Description |
|---|---|---|---|
| Minute | 1st | 0–59 |
Minute of the hour |
| Hour | 2nd | 0–23 |
Hour of the day |
| Day of Month | 3rd | 1–31 |
Day of the month |
| Month | 4th | 1–12 or JAN–DEC |
Month of the year |
| Day of Week | 5th | 0–6 or SUN–SAT |
Day of the week (0 = Sunday) |
| Syntax | Example | Description |
|---|---|---|
Asterisk * |
* * * * * |
Wildcard – every possible value |
List , |
0 9,17 * * * |
Multiple values – at 9:00 and 17:00 |
Range - |
0 9-17 * * * |
Range – every hour from 9:00 to 17:00 |
Step / |
*/15 * * * * |
Step – every 15 minutes |
- ✅ Real-time cron expression parsing
- ✅ Clean, terminal-inspired UI with light & dark modes
- ✅ Upcoming executions viewer (up to 5 future runs)
- ✅ Timezone support (IANA-compliant)
- ✅ Hover-based field highlighting tied to cursor position
- ✅ Copy cron expression to clipboard
- ✅ Smart cron templates (presets)
- ✅ Lightning Cron Challenges (mini quiz mode)
- ✅ Cron syntax reference with interactive formatting
Built with care by Jodi Gabano an IT Intern at Tutorials Dojo and BS Computer Science student at the University of the Philippines - Mindanao.