Azure Functions (NCRONTAB) Cron Expression Guide
Azure Functions uses NCRONTAB — a 6-field cron format with seconds prepended. The extra seconds field makes Azure expressions look different from standard 5-field cron but adds sub-minute precision.
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Valid
MINMinute
0HRHour
9DOMDay of Month
*MONMonth
*DOWDay of Week
1-5In plain English
At 09:00 AM, Monday through Friday
English → Cron
Try: "every 5 minutes", "every weekday at 9am", "every Monday at 3pm", "every month on the 1st"
Next 10 Executions
UTC- 1Mon, May 18, 09:00 AM UTCin 3d
- 2Tue, May 19, 09:00 AM UTCin 4d
- 3Wed, May 20, 09:00 AM UTCin 5d
- 4Thu, May 21, 09:00 AM UTCin 6d
- 5Fri, May 22, 09:00 AM UTCin 7d
- 6Mon, May 25, 09:00 AM UTCin 10d
- 7Tue, May 26, 09:00 AM UTCin 11d
- 8Wed, May 27, 09:00 AM UTCin 12d
- 9Thu, May 28, 09:00 AM UTCin 13d
- 10Fri, May 29, 09:00 AM UTCin 14d
crontab entrybash
# Add to crontab with: crontab -e
0 9 * * 1-5 /path/to/your/script.shSyntax Overview
Field order
SEC
Second
MIN
Minute
HR
Hour
DOM
Day of Month
MON
Month
DOW
Day of Week
0 0 9 * * 1-5Example: At 09:00 AM, Monday through Friday
⚠
Azure Functions uses a 6-field format with seconds as the first field.
Common Expressions
0 0 9 * * 1-5—Every weekday at 9am (seconds=0)0 */5 * * * *—Every 5 minutes0 0 0 * * *—Every day at midnight0 30 8 * * 1—Every Monday at 8:30am0 0 */6 * * *—Every 6 hours0 0 0 1 * *—1st of every month at midnightFrequently Asked Questions
Why does Azure Functions have 6 fields instead of 5? ▾
Azure Functions uses NCRONTAB, which prepends a seconds field. The format is: {second} {minute} {hour} {day} {month} {day-of-week}. Standard cron starts at minute; Azure starts at second.
Can I run an Azure Function every 30 seconds? ▾
Yes — "0,30 * * * * *" runs at the 0-second and 30-second mark of every minute. The seconds field enables sub-minute precision that standard 5-field cron cannot express.
Does Azure Functions timer trigger use UTC? ▾
By default, yes — Azure Functions runs in UTC. You can override this by setting the WEBSITE_TIME_ZONE application setting for Windows plans, or TZ for Linux. The cron expression is evaluated in the configured timezone.
What is the format for Azure Functions function.json timer binding? ▾
The timer binding in function.json uses the "schedule" property with an NCRONTAB expression: {"type": "timerTrigger", "direction": "in", "schedule": "0 */5 * * * *"}. The builder above generates this JSON automatically.
Why is my Azure timer function running more often than expected? ▾
Check whether the FUNCTIONS_WORKER_RUNTIME is set correctly and whether "runOnStartup" is true in your binding — if true, the function fires immediately when the host starts, in addition to the scheduled runs.