cronwtf

Cron expression decoder & generator. wtf does this cron do?

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Install

npm install -g cronwtf

Quick Start

# explain a cron expression
cronwtf "*/15 * * * *"
# Every 15 minutes

# validate expression
cronwtf validate "0 25 * * *"
# invalid: hour out of range

# show next runs
cronwtf next "0 9 * * 1-5"

# compare two expressions
cronwtf diff "0 9 * * *" "0 9 * * 1-5"

# generate from text (PRO)
cronwtf generate "every monday at 9am"

# convert formats (PRO)
cronwtf convert "0 9 * * 1-5" --to aws

Commands

FREE Commands

| Command | Description | Example | |---------|-------------|---------| | explain | Explain cron expression (default) | cronwtf "*/15 * * * *" | | validate | Check if expression is valid | cronwtf validate "0 9 * * *" | | next | Show next run times | cronwtf next "0 9 * * *" | | diff | Compare two expressions | cronwtf diff "0 9 * * *" "0 9 * * 1-5" |

PRO Commands

| Command | Description | Example | |---------|-------------|---------| | generate | Generate from plain English | cronwtf generate "every monday at 9am" | | convert | Convert between formats | cronwtf convert "0 9 * * *" --to aws | | calendar | Export to iCal | cronwtf calendar "0 9 * * 1-5" -o work.ics | | test | Test against dates | cronwtf test "0 9 * * *" --date "2024-12-25" | | interactive | Build step-by-step | cronwtf interactive |

Get PRO - One-time $8.99, no subscriptions.

Usage

Explain Cron

# default command
cronwtf "*/15 * * * *"
# Every 15 minutes

cronwtf "0 9 * * 1-5"
# At minute 0 at 9AM on weekdays

cronwtf "@daily"
# Every day at midnight

# JSON output
cronwtf "0 9 * * *" --json

Validate

cronwtf validate "0 9 * * *"
# valid cron expression. nice.

cronwtf validate "0 25 * * *"
# invalid: hour values out of range (25)

# strict mode for edge case warnings
cronwtf validate "* * * * *" --strict

Next Runs

# show next 5 runs
cronwtf next "0 9 * * *"

# show more runs
cronwtf next "0 9 * * *" -c 10

# different timezone (PRO)
cronwtf next "0 9 * * *" --timezone America/New_York

Compare

cronwtf diff "0 9 * * *" "0 9 * * 1-5"
# Shows differences and overlap

Generate (PRO)

cronwtf generate "every 5 minutes"
# */5 * * * *

cronwtf generate "every monday at 9am"
# 0 9 * * 1

cronwtf generate "first day of month at midnight"
# 0 0 1 * *

# show common patterns
cronwtf generate --examples

Convert (PRO)

# to AWS CloudWatch
cronwtf convert "0 9 * * 1-5" --to aws
# cron(0 9 ? * 2-6 *)

# to GitHub Actions
cronwtf convert "0 9 * * 1-5" --to github

# to systemd
cronwtf convert "0 9 * * 1-5" --to systemd

# from AWS to standard cron
cronwtf convert "cron(0 9 ? * 2-6 *)" --from aws

# supported formats
cronwtf convert --formats

Calendar Export (PRO)

# export to iCal file
cronwtf calendar "0 9 * * 1-5" -o standup.ics -n "Daily Standup"

# preview without exporting
cronwtf calendar "0 9 * * 1-5" --preview

Test Dates (PRO)

# test single date
cronwtf test "0 9 * * 1-5" --date "2024-12-25 09:00"

# test date range
cronwtf test "0 9 * * *" --range "2024-01-01..2024-01-07"

License Management

# show status
cronwtf license

# activate PRO
cronwtf license --key YOUR_LICENSE_KEY

# deactivate
cronwtf license --deactivate

Programmatic API

const cronwtf = require('cronwtf');

// Parse and validate
const parsed = cronwtf.parse('0 9 * * 1-5');
const { valid, errors } = cronwtf.validate('0 9 * * *');

// Get description
const desc = cronwtf.describe('*/15 * * * *');
// "Every 15 minutes"

// Get next occurrences
const next = cronwtf.getNextOccurrences('0 9 * * *', 5);

// Compare expressions
const diff = cronwtf.compare('0 9 * * *', '0 9 * * 1-5');

// Generate from text (PRO)
const { expression } = cronwtf.generate('every monday at 9am');

// Convert formats (PRO)
const aws = cronwtf.toAws('0 9 * * 1-5');
const github = cronwtf.toGitHub('0 9 * * 1-5');

Free vs PRO

| Feature | FREE | PRO | |---------|------|-----| | Explain expressions | Unlimited | Unlimited | | Validate expressions | Unlimited | Unlimited | | Compare expressions | Unlimited | Unlimited | | Next runs | 5 runs | 100 runs | | Daily operations | 10/day | Unlimited | | Timezones | Local only | All timezones | | Generate from text | - | Included | | Format conversion | - | All formats | | Calendar export | - | iCal/Google | | Date testing | - | Included | | Interactive builder | - | Included | | Price | Free | $8.99 (one-time) |

Get PRO - Unlimited everything. One-time purchase. No subscriptions.

Cron Format Reference

┌───────────── minute (0-59)
│ ┌───────────── hour (0-23)
│ │ ┌───────────── day of month (1-31)
│ │ │ ┌───────────── month (1-12 or jan-dec)
│ │ │ │ ┌───────────── day of week (0-7, 0 and 7 are Sunday)
│ │ │ │ │
* * * * *

Special Characters

| Character | Description | Example | |-----------|-------------|---------| | * | Any value | * * * * * (every minute) | | , | List | 0,30 * * * * (at 0 and 30) | | - | Range | 0 9-17 * * * (9am-5pm) | | / | Step | */15 * * * * (every 15) |

Aliases

| Alias | Equivalent | |-------|------------| | @yearly | 0 0 1 1 * | | @monthly | 0 0 1 * * | | @weekly | 0 0 * * 0 | | @daily | 0 0 * * * | | @hourly | 0 * * * * | | @reboot | Run at startup |

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License

MIT (c) rtfm.codes

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