RecurrenceTrigger - Quartznet

RecurrenceTrigger uses iCalendar RFC 5545 recurrence rules (RRULE) to define schedules. This trigger type enables complex scheduling patterns that cannot be expressed with CronTrigger or SimpleTrigger, such as "every 2nd Monday of the month", "every other week on Monday, Wednesday and Friday", or "the last weekday of March each year".

RecurrenceTrigger accepts a standard RRULE string and computes fire times lazily without materializing all occurrences.

RRULE Basics

An RRULE string defines a recurrence pattern using semicolon-separated key-value pairs. The FREQ property is required and specifies the base frequency. Other properties refine the pattern:

Property	Description	Example
`FREQ`	Base frequency (required)	`YEARLY`, `MONTHLY`, `WEEKLY`, `DAILY`, `HOURLY`, `MINUTELY`, `SECONDLY`
`INTERVAL`	How often the recurrence repeats (default: 1)	`INTERVAL=2` (every other)
`COUNT`	Maximum number of times the trigger will fire	`COUNT=10`
`UNTIL`	End date/time for the recurrence	`UNTIL=20251231T235959Z`
`BYDAY`	Days of the week, optionally with ordinal	`BYDAY=MO,WE,FR` or `BYDAY=2MO` (2nd Monday)
`BYMONTHDAY`	Days of the month (1-31 or -1 to -31)	`BYMONTHDAY=15` or `BYMONTHDAY=-1` (last day)
`BYMONTH`	Months of the year (1-12)	`BYMONTH=1,6,12`
`BYSETPOS`	Position within the expanded set	`BYSETPOS=-1` (last occurrence)
`BYHOUR`	Hours (0-23)	`BYHOUR=9,17`
`BYMINUTE`	Minutes (0-59)	`BYMINUTE=0,30`
`BYSECOND`	Seconds (0-59)	`BYSECOND=0`
`BYWEEKNO`	Week numbers (1-53 or -53 to -1)	`BYWEEKNO=1,26`
`BYYEARDAY`	Day of year (1-366 or -366 to -1)	`BYYEARDAY=1,100,200`
`WKST`	Week start day (default: `MO`)	`WKST=SU`

::: tip COUNT and UNTIL are mutually exclusive - you cannot use both in the same RRULE. :::

::: warning COUNT tracks the number of times the trigger has actually fired (via TimesTriggered), not the number of theoretical recurrence occurrences. Misfired occurrences that are skipped (e.g., via DoNothing misfire policy) do not count toward the limit. However, if the misfire policy causes an immediate fire (e.g., FireOnceNow), that fire does count. This is consistent with Quartz.NET trigger semantics but differs from strict RFC 5545 occurrence counting. :::

Examples

Every 2nd Monday of the month at 9:00 AM:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("monthlyTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=MONTHLY;BYDAY=2MO")
    .StartAt(DateBuilder.DateOf(9, 0, 0, 1, 1, 2025))
    .Build();

Every other week on Monday, Wednesday, and Friday:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("weeklyTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=WEEKLY;INTERVAL=2;BYDAY=MO,WE,FR")
    .StartNow()
    .Build();

Last weekday of March each year:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("yearlyTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=YEARLY;BYMONTH=3;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1")
    .StartNow()
    .Build();

Every day, but only on weekdays (skip weekends):

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("weekdayTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=DAILY;BYDAY=MO,TU,WE,TH,FR")
    .StartNow()
    .Build();

Last day of every month:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("lastDayTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=MONTHLY;BYMONTHDAY=-1")
    .StartNow()
    .Build();

Every 3 months on the 1st and 15th, limited to 10 occurrences:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("quarterlyTrigger", "group1")
    .WithRecurrenceSchedule("FREQ=MONTHLY;INTERVAL=3;BYMONTHDAY=1,15;COUNT=10")
    .StartNow()
    .Build();

Time Zone Support

By default, recurrence calculations use the system's local time zone. You can specify a different time zone using the builder's InTimeZone method:

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("trigger1", "group1")
    .WithRecurrenceSchedule("FREQ=MONTHLY;BYDAY=2MO", b => b
        .InTimeZone(Quartz.Util.TimeZoneUtil.FindTimeZoneById("Eastern Standard Time")))
    .StartNow()
    .Build();

DI / Hosted Service Configuration

When using AddQuartz() for dependency injection, configure a recurrence trigger with WithRecurrenceSchedule:

csharp

services.AddQuartz(q =>
{
    q.AddJob<MyJob>(j => j.WithIdentity("myJob"));
    q.AddTrigger(t => t
        .ForJob("myJob")
        .WithIdentity("myTrigger")
        .WithRecurrenceSchedule("FREQ=MONTHLY;BYDAY=2MO")
        .StartNow());
});

RecurrenceTrigger Misfire Instructions

RecurrenceTrigger has two trigger-specific misfire instructions (identical semantics to CronTrigger), plus the generic IgnoreMisfirePolicy:

MisfireInstruction.RecurrenceTrigger.FireOnceNow
MisfireInstruction.RecurrenceTrigger.DoNothing
MisfireInstruction.IgnoreMisfirePolicy

If the 'smart policy' instruction is used (the default), RecurrenceTrigger will use FireOnceNow.

csharp

ITrigger trigger = TriggerBuilder.Create()
    .WithIdentity("trigger1", "group1")
    .WithRecurrenceSchedule("FREQ=WEEKLY;BYDAY=MO", b => b
        .WithMisfireHandlingInstructionDoNothing())
    .Build();

When to Use RecurrenceTrigger vs Other Triggers

Scenario	Recommended Trigger
Fixed interval (every 10 seconds)	SimpleTrigger
Cron-expressible pattern (every weekday at 9am)	CronTrigger
Nth day-of-week in month (2nd Monday)	RecurrenceTrigger
Last weekday of a month	RecurrenceTrigger
Every other week on specific days	RecurrenceTrigger
Complex yearly patterns with BYSETPOS	RecurrenceTrigger
Calendar interval (every 5 months)	CalendarIntervalTrigger

Persistence

RecurrenceTrigger uses the existing QRTZ_SIMPROP_TRIGGERS table for persistence - no database schema changes are required. The RRULE string is stored in the STR_PROP_1 column (max 512 characters). The trigger type discriminator is RECUR.