crontab
Read a cron expression back in English, with its next runs
expression
30
minute
0–59
4
hour
0–23
*
day of month
1–31
*
month
1–12 or JAN–DEC
*
day of week
0–7 or SUN–SAT
At 04:30.
next runs — UTC
…
Shown in your browser’s timezone. Real cron uses the server’s — check timedatectl if they differ.
examples
Macros: @yearly, @annually, @monthly, @weekly, @daily, @midnight, @hourly. When both day-of-month and day-of-week are restricted, cron runs when either matches — not both.