15 0 * * * — what this cron expression means

The cron expression 15 0 * * * runs at 00:15 every day. Here is the field-by-field breakdown and what it means in plain English.

Cron expression (minute hour day-of-month month day-of-week)

What 15 0 * * * means

It runs at 00:15 every day.

minute=15, hour=0, day-of-month=*, month=*, day-of-week=*.

Minute 15, hour 0 means 15 minutes past midnight, every day.

The next run is the next time the clock matches: at 00:15 every day.

It runs once a day at 00:15 — a quarter past midnight.

Staggering a few minutes past 00:00 avoids the pile-up of jobs that all fire at 0 0 * * *.