Cron Dialect Compatibility Matrix

POSIX cron

5 fields

minute · hour · day of month · month · day of week

Seconds: no · Year: no

5 minutes

Best effort; scheduled runs can be delayed

0-6 or SUN-SAT; Sunday is 0

POSIX day-of-month/day-of-week semantics

Runs the latest commit on the default branch and can be delayed under load.

*, lists, ranges, steps; numeric or named months/weekdays

AWS cron(...)

6 fields

minute · hour · day of month · month · day of week · year

Seconds: no · Year: yes

1 minute

60 seconds unless a flexible window widens delivery

1-7 or SUN-SAT

Constrain one day field and use ? in the other

It resembles Quartz but starts with minutes and requires a year field.

?, L, W, # plus lists, ranges, and steps

Restricted 5-field cron

5 fields

minute · hour · day of month · month · day of week

Seconds: no · Year: no

Hobby: once/day; other plans have minute-level expressions

Hobby: within the hour; other teams: within the minute

0-6; Sunday is 0; numeric only

Only one of day of month and day of week may be constrained

No automatic failure retry; duplicate and overlapping invocations are possible.

Numeric values; no MON/SUN/JAN/DEC aliases

Spring cron

6 fields

second · minute · hour · day of month · month · day of week

Seconds: yes · Year: no

1 second in the expression grammar

Application scheduler and executor dependent

0-7 or MON-SUN; Sunday is 0 or 7

Spring cron day rules; ? is supported for an unspecified day field

It is not identical to Quartz: there is no year and weekday numbering differs.

?, L, W, # and @yearly/@monthly/@weekly/@daily/@hourly macros

OnCalendar calendar event

Calendar syntax, not fixed cron fields

weekday (optional) · date (optional) · time (optional) · timezone (optional)

Seconds: yes · Year: yes

Seconds are supported; behavior also depends on AccuracySec

AccuracySec defaults to 1 minute

English weekday names, lists, and ranges

Date and weekday components must both match when both are present

OnCalendar is not cron; validate it on the target host with systemd-analyze calendar.

Calendar dates, repetition, timezone suffixes, and readable shorthands

5-field cron

5 fields

minute · hour · day of month · month · day of week

Seconds: no · Year: no

1 minute (account limits apply)

Edge invocation; subject to Worker limits

0-6; Sunday is 0

Standard cron day semantics

Always UTC — convert local business hours before deploy.

Configured in wrangler.toml [triggers] crons

NCRONTAB (6-field)

6 fields

second · minute · hour · day · month · day of week

Seconds: yes · Year: no

1 second in expression grammar

Plan and cold-start dependent

0-6; ? supported

Azure NCRONTAB day field rules

Five-field Unix cron requires prepending a seconds field.

? wildcard for day fields

5-field cron

5 fields

minute · hour · day of month · month · day of week

Seconds: no · Year: no

1 minute

In-database worker

0-7; 0 and 7 = Sunday

Standard cron

Runs SQL only — not shell commands.

cron.schedule(name, cron, SQL command)

PHP schedule API + one crontab line

5 (via ->cron() or helpers) fields

minute · hour · day of month · month · day of week

Seconds: no · Year: no

1 minute (schedule:run must run every minute)

Depends on server crontab reliability

0-7 in underlying cron strings

Standard when using ->cron()

Missing * * * * * schedule:run crontab line stops all tasks.

dailyAt(), hourly(), cron() helpers