How does NCRONTAB differ from standard cron?

NCRONTAB adds a seconds field as the first position, making it a six-field format: {second} {minute} {hour} {day} {month} {day-of-week}. Standard cron uses five fields without seconds. For example, '0 */5 * * * *' in NCRONTAB runs every 5 minutes at second zero, whereas '*/5 * * * *' is the five-field cron equivalent.

What timezone do Azure Functions timer triggers use?

By default, Azure Functions timer triggers use UTC. You can set the WEBSITE_TIME_ZONE application setting to use a specific timezone (e.g., 'Eastern Standard Time' on Windows or 'America/New_York' on Linux). This affects when the NCRONTAB expression evaluates.

Can multiple Function instances fire the same timer?

By default, timer triggers use a distributed lock (via Azure Storage) to ensure only one instance runs the function at each scheduled time, even when scaled out to multiple instances. You can disable this with the useMonitor setting if you want all instances to fire.

Azure NCRONTAB Helper

ServerlessAzure

Build and validate NCRONTAB expressions for Azure Functions timer triggers.

NCRONTAB Expression

Mode

Common Presets

Second (0-59)

*, 0-59, */N, ranges, lists

Minute (0-59)

*, 0-59, */N, ranges, lists

Hour (0-23)

*, 0-23, */N, ranges, lists

Day of Month (1-31)

*, 1-31, */N, ranges, lists

Month (1-12)

*, 1-12, */N, ranges, lists

Day of Week (0-6, 0=Sun)

*, 0-6, ranges (1-5), lists (1,3,5)

Expression Preview

0 * * * * *

Output

Output will appear here...

About This Tool

The Azure NCRONTAB Helper builds and validates NCRONTAB expressions used by Azure Functions timer triggers. NCRONTAB extends standard cron syntax with a sixth field for seconds, giving you sub-minute scheduling precision. The tool shows next execution times, translates expressions into human-readable descriptions, and warns about common pitfalls like timezone handling and host synchronization.

When to Use This Tool

•Building a timer trigger expression for an Azure Function that runs every 30 seconds during business hours.
•Validating that an NCRONTAB expression fires at the expected times before deploying a Function App.
•Converting standard five-field cron expressions to NCRONTAB format with the seconds field.
•Debugging timer trigger schedules that fire at unexpected times due to timezone misconfiguration.

Frequently Asked Questions

How does NCRONTAB differ from standard cron?: NCRONTAB adds a seconds field as the first position, making it a six-field format: {second} {minute} {hour} {day} {month} {day-of-week}. Standard cron uses five fields without seconds. For example, '0 */5 * * * *' in NCRONTAB runs every 5 minutes at second zero, whereas '*/5 * * * *' is the five-field cron equivalent.
What timezone do Azure Functions timer triggers use?: By default, Azure Functions timer triggers use UTC. You can set the WEBSITE_TIME_ZONE application setting to use a specific timezone (e.g., 'Eastern Standard Time' on Windows or 'America/New_York' on Linux). This affects when the NCRONTAB expression evaluates.
Can multiple Function instances fire the same timer?: By default, timer triggers use a distributed lock (via Azure Storage) to ensure only one instance runs the function at each scheduled time, even when scaled out to multiple instances. You can disable this with the useMonitor setting if you want all instances to fire.

Related Learning Guides

Functions Hosting Plans22 min read
Cost Management Guide24 min read

Disclaimer: This tool runs entirely in your browser. No data is sent to our servers. Always verify outputs before using them in production. AWS, Azure, and GCP are trademarks of their respective owners.

Azure NCRONTAB Helper

ServerlessAzure

Build and validate NCRONTAB expressions for Azure Functions timer triggers.

NCRONTAB Expression

Mode

Common Presets

Second (0-59)

*, 0-59, */N, ranges, lists

Minute (0-59)

*, 0-59, */N, ranges, lists

Hour (0-23)

*, 0-23, */N, ranges, lists

Day of Month (1-31)

*, 1-31, */N, ranges, lists

Month (1-12)

*, 1-12, */N, ranges, lists

Day of Week (0-6, 0=Sun)

*, 0-6, ranges (1-5), lists (1,3,5)

Expression Preview

0 * * * * *

Output

Output will appear here...

About This Tool

When to Use This Tool

•Building a timer trigger expression for an Azure Function that runs every 30 seconds during business hours.
•Validating that an NCRONTAB expression fires at the expected times before deploying a Function App.
•Converting standard five-field cron expressions to NCRONTAB format with the seconds field.
•Debugging timer trigger schedules that fire at unexpected times due to timezone misconfiguration.

Frequently Asked Questions

How does NCRONTAB differ from standard cron?: NCRONTAB adds a seconds field as the first position, making it a six-field format: {second} {minute} {hour} {day} {month} {day-of-week}. Standard cron uses five fields without seconds. For example, '0 */5 * * * *' in NCRONTAB runs every 5 minutes at second zero, whereas '*/5 * * * *' is the five-field cron equivalent.
What timezone do Azure Functions timer triggers use?: By default, Azure Functions timer triggers use UTC. You can set the WEBSITE_TIME_ZONE application setting to use a specific timezone (e.g., 'Eastern Standard Time' on Windows or 'America/New_York' on Linux). This affects when the NCRONTAB expression evaluates.
Can multiple Function instances fire the same timer?: By default, timer triggers use a distributed lock (via Azure Storage) to ensure only one instance runs the function at each scheduled time, even when scaled out to multiple instances. You can disable this with the useMonitor setting if you want all instances to fire.

Related Learning Guides

Functions Hosting Plans22 min read
Cost Management Guide24 min read