Crontab Wizard

Explain, generate, validate, and preview crontab expressions. Use when a user needs to understand what a cron expression means, create a new cron schedule, check if a cron expression is valid, or see when a cron job will run next. Supports standard 5-field cron syntax and shortcuts like @daily, @hourly, @weekly. No dependencies required.

Decode, generate, validate, and preview cron schedules from the command line. Zero dependencies.

Quick Start

bash

# Explain what a cron expression does
python3 scripts/cronwiz.py explain "*/5 * * * *"

# Generate an expression from options
python3 scripts/cronwiz.py generate --every 5m

# Check if an expression is valid
python3 scripts/cronwiz.py validate "0 9 * * 1-5"

# See when it runs next
python3 scripts/cronwiz.py next "0 9 * * 1-5" --count 10

Commands

explain — Decode cron to plain English

bash

python3 scripts/cronwiz.py explain "30 2 * * 0"
# → At 02:30, on Sunday

python3 scripts/cronwiz.py explain "@daily"
# → At 00:00

python3 scripts/cronwiz.py explain "0 */6 * * *"
# → At minute 0, every 6 hours

validate — Check for errors

bash

python3 scripts/cronwiz.py validate "0 9 * * 1-5"
# → VALID: 0 9 * * 1-5

python3 scripts/cronwiz.py validate "0 25 * * *"
# → INVALID: hour: 25 out of range (0-23)

next — Preview upcoming runs

bash

python3 scripts/cronwiz.py next "0 9 * * 1-5" --count 5
# Shows next 5 weekday 9 AM runs with dates

generate — Build expressions from options

bash

python3 scripts/cronwiz.py generate --every 5m
# → */5 * * * *

python3 scripts/cronwiz.py generate --every daily --at 09:00
# → 0 9 * * *

python3 scripts/cronwiz.py generate --every week --at 14:30 --on friday
# → 30 14 * * 5

Generate options

Flag	Values	Description
--every	5m, 2h, daily, weekly, monthly	Interval
--at	HH:MM	Time of day
--on	mon–sun, weekdays, weekends	Day of week

Supported Shortcuts

@yearly, @annually, @monthly, @weekly, @daily, @midnight, @hourly

Dependencies

None — pure Python, no pip installs required.