Quartz Cron Expression Generator

This is the most misunderstood part of Quartz syntax. * and ? look similar but mean different things:

• * in DOM means every day of the month - the job fires on all 28-31 days.
• ? in DOM means not specified - day-of-month is irrelevant because day-of-week already constrains the schedule.

When one of day-of-month or day-of-week is specified, the other should use ? to indicate it is not relevant. Quartz does not support specifying both fields simultaneously.

0 0 9 ? * MON-FRI   # correct: DOW=MON-FRI, DOM=? (irrelevant)
0 0 9 15 * ?        # correct: DOM=15th, DOW=? (irrelevant)
0 0 9 * * MON-FRI   # WRONG: both DOM and DOW specified
0 0 9 * * *         # WRONG in Quartz: neither is ?

Linux cron uses OR logic instead - if you set both DOM and DOW, the job fires when either condition is true. Quartz does not allow this ambiguity.

Full Java Quartz CronTrigger setup with timezone:

CronTrigger trigger = TriggerBuilder.newTrigger()
    .withIdentity("myTrigger", "group1")
    .withSchedule(CronScheduleBuilder
        .cronSchedule("0 0 9 ? * MON-FRI")
        .inTimeZone(TimeZone.getTimeZone("Europe/Madrid")))
    .build();

See the Quartz CronTrigger documentation.

Without explicit timezone configuration, Quartz uses the JVM default - often a source of bugs when servers run UTC but schedules are written in local time:

// Java Quartz
CronScheduleBuilder.cronSchedule("0 0 9 ? * MON-FRI")
    .inTimeZone(TimeZone.getTimeZone("UTC"))

// Spring Boot @Scheduled
@Scheduled(cron = "0 0 9 ? * MON-FRI", zone = "Europe/Madrid")

// Databricks
schedule:
  quartz_cron_expression: "0 0 9 ? * MON-FRI"
  timezone_id: "Europe/Madrid"

// Quartz.NET
.WithCronSchedule("0 0 9 ? * MON-FRI",
    x => x.InTimeZone(TimeZoneInfo.FindSystemTimeZoneById("UTC")))

Java Quartz optionally accepts a 7th field - Year - at the end. Spring Boot does not support the year field (6 fields only). Databricks does not support it either.

0 0 2 ? * SAT 2026        # Sat 2 AM, 2026 only
0 0 0 1 1 ? 2026-2028     # Jan 1st midnight, years 2026-2028
0 0 9 ? * MON-FRI *       # any year (explicit, same as omitting)

Omit the year field and Quartz defaults to *. Use it when the schedule should be restricted to specific years or a year range - for example, a migration job that should only run in 2026-2028.

Databricks Jobs use Quartz cron syntax (6-field, no year) in quartz_cron_expression, with timezone as a separate timezone_id field:

schedule:
  quartz_cron_expression: "0 0 6 ? * MON-FRI"
  timezone_id: "UTC"

Use 6 fields only. The timezone_id must be a valid IANA timezone string (e.g. "Europe/Madrid", "America/New_York").

Quartz.NET is an independent .NET port. Core syntax is compatible with Java Quartz. Quartz.NET 3.x supports all standard operators including W, and additionally adds the H hash token - not present in Java Quartz - which distributes triggers across a time window to avoid simultaneous firing:

ITrigger trigger = TriggerBuilder.Create()
    .WithCronSchedule("0 0 9 ? * MON-FRI",
        x => x.InTimeZone(TimeZoneInfo.FindSystemTimeZoneById("UTC")))
    .Build();

If you are on Quartz.NET 2.x, verify W and L behaviour against your specific version as support varied across releases. See the Quartz.NET 3.x CronTrigger documentation.