Awesome Open Source
Awesome Open Source


Build PkgGoDev Go Report Card codecov

A minimalistic and zero-dependency scheduling library for Go.


Inspired by the Quartz Java scheduler.

Library building blocks

Scheduler interface

type Scheduler interface {
	// Start starts the scheduler. The scheduler will run until
	// the Stop method is called or the context is canceled. Use
	// the Wait method to block until all running jobs have completed.
	// IsStarted determines whether the scheduler has been started.
	IsStarted() bool
	// ScheduleJob schedules a job using a specified trigger.
	ScheduleJob(ctx context.Context, job Job, trigger Trigger) error
	// GetJobKeys returns the keys of all of the scheduled jobs.
	GetJobKeys() []int
	// GetScheduledJob returns the scheduled job with the specified key.
	GetScheduledJob(key int) (*ScheduledJob, error)
	// DeleteJob removes the job with the specified key from the Scheduler's execution queue.
	DeleteJob(key int) error
	// Clear removes all of the scheduled jobs.
	// Stop shutdowns the scheduler.
	// Wait blocks until the scheduler stops running and all jobs
	// have returned. Wait will return when the context passed to
	// it has expired. Until the context passed to start is
	// cancelled or Stop is called directly.

Implemented Schedulers

  • StdScheduler

Trigger interface

type Trigger interface {
	// NextFireTime returns the next time at which the Trigger is scheduled to fire.
	NextFireTime(prev int64) (int64, error)
	// Description returns the description of the Trigger.
	Description() string

Implemented Triggers

  • CronTrigger
  • SimpleTrigger
  • RunOnceTrigger

Job interface. Any type that implements it can be scheduled.

type Job interface {
	// Execute is called by a Scheduler when the Trigger associated with this job fires.
	// Description returns the description of the Job.
	Description() string
	// Key returns the unique key for the Job.
	Key() int

Implemented Jobs

  • ShellJob
  • CurlJob
  • FunctionJob

Cron expression format

Field Name Mandatory Allowed Values Allowed Special Characters
Seconds YES 0-59 , - * /
Minutes YES 0-59 , - * /
Hours YES 0-23 , - * /
Day of month YES 1-31 , - * ? /
Month YES 1-12 or JAN-DEC , - * /
Day of week YES 1-7 or SUN-SAT , - * ? /
Year NO empty *


ctx := context.Background()
sched := quartz.NewStdScheduler()
cronTrigger, _ := quartz.NewCronTrigger("1/5 * * * * *")
shellJob := quartz.NewShellJob("ls -la")
curlJob, _ := quartz.NewCurlJob(http.MethodGet, "", "", nil)
functionJob := quartz.NewFunctionJob(func(_ context.Context) (int, error) { return 42, nil })
sched.ScheduleJob(shellJob, cronTrigger)
sched.ScheduleJob(curlJob, quartz.NewSimpleTrigger(time.Second*7))
sched.ScheduleJob(functionJob, quartz.NewSimpleTrigger(time.Second*5))

More code samples can be found in the examples directory.


Licensed under the MIT License.

Get A Weekly Email With Trending Projects For These Topics
No Spam. Unsubscribe easily at any time.
Golang (171,827
Cron (5,637
Crontab (2,470
Quartz (1,117
Job Scheduler (415
Job Queue (413
Zero Dependency (151