Cron vs systemd timers: which scheduler should you use on modern Linux?

How this is calculated

Systemd timers support features cron doesn't: randomized start delays (RandomizedDelaySec) to avoid thundering herds, monotonic timers (OnUnitActiveSec) that fire relative to the last completion rather than wall clock time, sub-second precision, and proper dependency management between services. Cron's advantages are that it works on every Unix-like system including macOS, FreeBSD, and minimal containers, and its syntax is known by every sysadmin. If you're scheduling on a single server and don't need the advanced features, cron is fine. If you're deploying to a fleet of Linux servers and need coordinated timing, randomized jitter, or sub-minute scheduling, systemd timers are the right choice.

Verdict

Use cron for simplicity, portability, and when you're on a non-systemd system. Use systemd timers when you need randomized delays, sub-minute precision, monotonic scheduling, or tight integration with systemd service management. Both are viable on modern Linux. The decision is about your specific operational requirements.