Azure Cron Generator

Azure Cron Generator for Functions Timer Triggers

Create an Azure cron schedule without calculating every field by hand. This generator builds an explicit six-field NCRONTAB expression for an Azure Functions Timer Trigger, explains when it runs, and provides configuration or code examples you can copy into your project.

This page is intended for developers searching for an Azure cron expression, Azure cron schedule, or a way to run a recurring cron job in Azure Functions. It is not a generator for Azure DevOps Pipeline schedules, which use a different five-field YAML cron format.

How to Generate an Azure Cron Expression

1. Choose the second, minute, hour, day of month, month, and day of week.
2. Check the generated schedule description to confirm the timing.
3. Copy the NCRONTAB expression or the available Azure Functions code/configuration example.
4. Paste the schedule into your Timer Trigger and test it before production deployment.

The generator uses the unambiguous field order {second} {minute} {hour} {day} {month} {day-of-week}. Microsoft documents both five- and six-field NCRONTAB expressions for Timer Triggers; using all six fields makes the seconds value explicit.

Azure NCRONTAB Fields

Use * for every value, a comma for a list such as 1,3,5, a hyphen for a range such as 1-5, and a slash for a step such as */15.

Common Azure Cron Schedule Examples

Worked Example: Run Every Weekday at 9:30 AM

To run a reporting function Monday through Friday at 9:30 AM, use:

0 30 9 * * 1-5

The first 0 means second zero, 30 is the minute, 9 is the hour, the two asterisks allow every date and month, and 1-5 limits execution to Monday through Friday. Azure evaluates this at 9:30 AM UTC by default, unless the Function App uses a supported time-zone configuration.

For a C# isolated-worker function, the schedule can be placed directly in the trigger attribute:

[Function("WeekdayReport")]
            public void Run([TimerTrigger("0 30 9 * * 1-5")] TimerInfo timer)
            {
               // Generate the report.
            }

UTC and Local Time in Azure Functions

Azure Functions Timer Trigger cron schedules use UTC by default. If a job must follow local civil time and daylight-saving changes, Microsoft supports the WEBSITE_TIME_ZONE app setting on Windows plans and on Linux Premium or Dedicated plans. It is not supported for Linux Flex Consumption or Linux Consumption plans, so use a UTC schedule there and account for seasonal clock changes in your design.

Common Errors

• Using Linux field order: a traditional five-field expression starts with minutes; this generator outputs seconds first.
• Reading an hour as an interval: 5 in the hour field means 5:00 AM, while */5 means an interval of five hours.
• Ignoring UTC: 0 0 9 * * * is 9:00 AM UTC unless a supported time zone is configured.
• Expecting unsupported Quartz syntax: verify advanced characters before deployment; NCRONTAB is not identical to every cron dialect.
• Confusing Azure services: Azure Functions and WebJobs NCRONTAB schedules differ from Azure DevOps Pipeline cron syntax.

Best Practices

• Keep schedules in UTC when possible to avoid daylight-saving surprises.
• Store environment-specific schedules in an app setting and reference it as %ScheduleAppSetting%.
• Make the function idempotent so a retry or repeated invocation does not duplicate work.
• Choose an interval longer than the normal processing time and monitor executions with Application Insights.
• Test the next expected run in a development or staging Function App before publishing to production.

Frequently Asked Questions