Cron Timer Designer is a desktop schedule builder, trigger timeline simulator, and systemd unit generator for Linux developers and system administrators. Build 5-field cron expressions and presets interactively, verify plain-English schedule meanings in real time, preview the exact next 25 execution timestamps on a 24-hour density heatmap, and export production-ready crontab entries alongside matching systemd .service and .timer unit files.

Key Features:

• Interactive 5-Field Cron & Systemd OnCalendar Builder: Visual minute, hour, day-of-month, month, and weekday pickers synchronized with raw expression input, standard macros (@hourly, @daily, every 15 min, weekdays 9 AM), plain-English translation, systemd OnCalendar conversion, and syntax error diagnostics.
• Next 25 Trigger Simulator & 24-Hour Density Grid: Pure-Python schedule matcher computing the exact next 25 trigger timestamps in local and UTC time alongside a custom 24-hour x 7-day execution density heatmap.
• Crontab & Systemd Unit Exporter: Generates ready-to-deploy crontab entries, matching .service and .timer systemd unit files with Persistent and RandomizedDelaySec options, plus CSV next-25 schedule export.

Disclaimer: Cron Timer Designer is an independent open-source project by TC Studio and is not affiliated with, endorsed by, or sponsored by Crontab.guru.