What is Scheduled Apex?

Scheduled Apex is a class that implements Schedulable and runs on a cron schedule. You register the class with a cron expression — “every day at 2 AM,” “every Sunday at midnight,” “on the 1st of the month” — and Salesforce invokes it at those times. It’s the Salesforce equivalent of a cron job.

The minimal shape

public class NightlyCleanup implements Schedulable {
    public void execute(SchedulableContext ctx) {
        // The work you want to run on schedule
        Database.executeBatch(new StaleCaseCleanupBatch(), 200);
    }
}

The interface has one method, execute(SchedulableContext). Salesforce calls it at every scheduled fire time.

Scheduling a class

Two options.

From Apex, using System.schedule

String cronExp = '0 0 2 * * ?'; // 2:00 AM every day
String jobName = 'NightlyCleanup';
Id jobId = System.schedule(jobName, cronExp, new NightlyCleanup());

System.schedule(name, cronExpression, instance) returns the JobId of the scheduled job. The job appears in Setup → Scheduled Jobs.

From the UI

Setup → Apex Classes → Schedule Apex lets admins pick a class and define the schedule with a form. No code required.

The Salesforce cron expression

Salesforce uses seconds-precision cron with seven fields:

Seconds  Minutes  Hours  Day-of-Month  Month  Day-of-Week  [Year]

Common expressions:

0 0 2 * * ?           Every day at 2:00 AM
0 30 4 * * ?          Every day at 4:30 AM
0 0 12 ? * SUN        Every Sunday at noon
0 0 0 1 * ?           First day of every month at midnight
0 0 9 ? * MON-FRI     Every weekday at 9 AM

Note: Day-of-Month and Day-of-Week can’t both have explicit values — one of them must be ?.

What you’d typically run

Pure Schedulable code is rare in real orgs. The pattern is Schedulable → Batch or Schedulable → Queueable:

public class NightlyCleanup implements Schedulable {
    public void execute(SchedulableContext ctx) {
        Database.executeBatch(new StaleCaseCleanupBatch(), 200);
    }
}

Reasons to wrap a Batch in a Schedulable:

• Schedulable doesn’t get the higher async governor limits — Batch does.
• Schedulable can’t directly make callouts; Queueable / Batch can.
• You almost always want to process records, and Batch handles volume natively.

Limits to remember

Aborting a scheduled job

System.abortJob(jobId);

Or via Setup → Scheduled Jobs → Delete.

Common interview follow-ups

• Which interface does Scheduled Apex implement? — Schedulable. One mandatory method: execute(SchedulableContext).
• Can I make callouts from Schedulable? — Not directly. The Schedulable execute runs without callout support; hand off to @future(callout=true) or a Queueable with Database.AllowsCallouts.
• Can I edit the class while it’s scheduled? — No. Scheduled classes are locked from edits until you unschedule all references. Same for any class referenced from the schedulable.

Verified against: Apex Developer Guide — Scheduled Apex. Last reviewed 2026-05-17 for Spring ‘26.