How do I schedule on the last day of every month in AWS?

Use cron(0 0 L * ? *). The L in day-of-month means the last day of the month. Day-of-week must be ? when day-of-month has a value.

AWS EventBridge Cron Expression Generator

Free AWS cron expression generator, parser, and translator for EventBridge & Scheduler

Use this free AWS EventBridge cron expression generator to build, parse, and validate Amazon EventBridge 6-field cron schedules. Paste any cron(...) or rate(...) expression to translate it to plain English and preview the next UTC run times. Compatible with EventBridge Rules, EventBridge Scheduler, CloudWatch Events, and Lambda schedules.

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UTC by default. EventBridge Rules always run in UTC. EventBridge Scheduler can use a timezone you choose. This tool shows next runs in UTC. AWS cron needs 6 fields (year required) and ? in one day field.

Choose Parse & Translate to paste an existing AWS schedule, or Generate to build a valid cron(...) expression from dropdowns.

Enter AWS cron or rate expression:

0 min

18 hour

? day(M)

* month

2-6 day(W)

* year

Translation (Human Readable)

Enter an AWS EventBridge cron or rate expression above

Next 3 Scheduled Runs (UTC)

Enter an expression to see upcoming runs

Minute

Hour

Day (Month)

Month

Day (Week)

Year

cron(0 18 ? * MON-FRI *)

Human Readable

At 6:00 PM, Mon through Fri (UTC)

Next 3 Runs (UTC)

Build an expression to see upcoming runs

AWS EventBridge Cron Quick Reference

Field Values (6 required)

Minutes	0-59
Hours	0-23
Day-of-month	1-31
Month	1-12 / JAN-DEC
Day-of-week	1-7 / SUN-SAT
Year	1970-2199 (required)

Special Characters

`*`	Any value
`?`	No specific value (day fields)
`,`	List separator
`-`	Range
`/`	Step values
`L`	Last (day/weekday)
`W`	Nearest weekday
`#`	Nth occurrence

AWS Rate Expression Builder

Prefer a fixed interval? EventBridge also accepts rate expressions. Build one here and copy it into your schedule.

Every Every 5 minutes

rate(5 minutes)

AWS EventBridge Cron Expression Examples

Click any expression to load it into the parser. All examples are valid for EventBridge Rules, EventBridge Scheduler, and Lambda schedule expressions.

AWS Expression	Description	Category
`cron(0 12 * * ? *)`	Every day at noon UTC	Daily
`cron(0 0 * * ? *)`	Every day at midnight UTC	Daily
`cron(0 6 * * ? *)`	Every day at 6 AM UTC	Daily
`cron(0 9 * * ? *)`	Every day at 9 AM UTC	Daily
`cron(0 18 * * ? *)`	Every day at 6 PM UTC	Daily
`cron(0 9,18 * * ? *)`	Twice daily (9 AM and 6 PM)	Daily
`cron(0/5 * * * ? *)`	Every 5 minutes	Interval
`cron(0/15 * * * ? *)`	Every 15 minutes	Interval
`cron(0/30 * * * ? *)`	Every 30 minutes	Interval
`cron(0 /2 * ? *)`	Every 2 hours	Interval
`cron(0 /6 * ? *)`	Every 6 hours	Interval
`cron(0/5 8-17 ? * MON-FRI *)`	Every 5 min, business hours	Interval
`cron(0 18 ? * MON-FRI *)`	Weekdays at 6 PM UTC	Weekday
`cron(0 9 ? * MON-FRI *)`	Weekdays at 9 AM UTC	Weekday
`cron(0 10 ? * SUN,SAT *)`	Weekends at 10 AM UTC	Weekday
`cron(0 0 ? * MON *)`	Every Monday at midnight	Weekday
`cron(0 15 ? * FRI *)`	Every Friday at 3 PM	Weekday
`cron(0 0 1 * ? *)`	First day of month at midnight	Monthly
`cron(0 0 15 * ? *)`	15th of month at midnight	Monthly
`cron(0 0 L * ? *)`	Last day of month at midnight	AWS Special
`cron(0 0 LW * ? *)`	Last weekday of month	AWS Special
`cron(0 0 15W * ? *)`	Nearest weekday to the 15th	AWS Special
`cron(15 10 ? * 6L *)`	Last Friday at 10:15	AWS Special
`cron(0 8 ? * 3#2 *)`	Second Tuesday at 8 AM	AWS Special
`cron(0 0 1 1 ? *)`	New Year's Day at midnight	Yearly
`cron(0 0 1 1,4,7,10 ? *)`	Quarterly (Jan, Apr, Jul, Oct)	Yearly
`rate(5 minutes)`	Every 5 minutes	Rate
`rate(1 hour)`	Every hour	Rate
`rate(1 day)`	Every day	Rate

AWS EventBridge Cron Syntax Guide

Understanding AWS EventBridge Cron Expressions

An AWS EventBridge cron expression defines when a schedule fires. It has six required fields, wrapped in cron(...), and is used by Amazon EventBridge Rules, EventBridge Scheduler, CloudWatch Events, and Lambda. Unlike Linux crontab (5 fields), AWS always includes a year field and requires the ? wildcard in one day field.

cron(minutes hours day-of-month month day-of-week year)

┌───────────── minutes (0-59)
│ ┌───────────── hours (0-23)
│ │ ┌───────────── day-of-month (1-31)
│ │ │ ┌───────────── month (1-12 or JAN-DEC)
│ │ │ │ ┌───────────── day-of-week (1-7 or SUN-SAT)
│ │ │ │ │ ┌───────── year (1970-2199)
│ │ │ │ │ │
0 18 ? * MON-FRI *

AWS Cron vs Linux Cron: Key Differences

Field Count and Wrapper

Linux crontab uses 5 fields. AWS uses 6 fields inside cron(...). A bare 5-field string like 0 9 * * 1-5 is rejected. Convert it to cron(0 9 ? * MON-FRI *). Need the standard format? Use our Cron Expression Generator.

The ? Requirement

You cannot set both day-of-month and day-of-week. One must be ?. This is the most common AWS scheduling mistake. If you constrain weekdays, put ? in day-of-month. If you constrain a date, put ? in day-of-week.

Day-of-Week Numbering

AWS numbers weekdays 1-7 where 1 = Sunday (same as Quartz). You can also use names: SUN, MON, TUE, WED, THU, FRI, SAT. Linux cron uses 0-6 with Sunday = 0.

Timezone

EventBridge Rules always use UTC. EventBridge Scheduler lets you pick a timezone. Confirm which product you are configuring before scheduling for a local business window.

AWS Special Characters Explained

? (No Specific Value)

Required in either day-of-month or day-of-week. Example: cron(0 18 ? * MON-FRI *) means 6 PM UTC on weekdays.

L (Last)

In day-of-month, L is the last day of the month. In day-of-week, 6L is the last Friday. Example: cron(0 0 L * ? *) fires at midnight on the last day of every month.

W (Nearest Weekday)

In day-of-month only. 15W means the nearest weekday to the 15th. LW means the last weekday of the month.

# (Nth Occurrence)

In day-of-week only. 3#2 means the second Tuesday of the month (3 = Tuesday). You can define only one # expression in the field — lists with # are invalid.

Rate Expressions

For fixed intervals, AWS also supports rate expressions: rate(value unit). Units are minute/minutes, hour/hours, or day/days. Use the singular form when value is 1: rate(1 hour), not rate(1 hours). Examples: rate(5 minutes), rate(12 hours), rate(1 day).

Where to Use AWS Cron Expressions

EventBridge Rules: Schedule expression in the console or ScheduleExpression API parameter.
EventBridge Scheduler: Preferred for new workloads. Supports timezones and one-time schedules.
Lambda: Event source schedules that invoke your function on a cron or rate.
Terraform: aws_cloudwatch_event_rule or aws_scheduler_schedule with schedule_expression.
CloudFormation / CDK: Same cron(...) and rate(...) strings in schedule properties.

Common AWS Cron Mistakes

Missing year field: Pasting a 5-field Linux expression. Always add year (usually *).
Both day fields set: Forgetting ?. One of day-of-month or day-of-week must be ?.
Missing cron() wrapper: AWS expects cron(0 18 ? * MON-FRI *), not the bare fields alone (in console/API schedule fields).
Timezone surprise: Scheduling for 9 AM local when the rule runs in UTC.
Using L/W/# in Linux cron: These only work in AWS (and Quartz). Standard crontab rejects them.

AWS EventBridge Cron FAQ

What is an AWS EventBridge cron expression?

An AWS EventBridge cron expression is a 6-field schedule string used by Amazon EventBridge Rules, EventBridge Scheduler, CloudWatch Events, and Lambda. The format is cron(minutes hours day-of-month month day-of-week year). Unlike Linux crontab (5 fields), AWS requires a year field and ? in one of the day fields.

How is AWS EventBridge cron different from Linux cron?

Linux crontab uses 5 fields. AWS uses 6 fields inside cron(...), requires a year field, requires ? in one day field, numbers weekdays 1-7 (Sunday=1), and supports L, W, and #. Use our standard Cron tool for 5-field expressions.

What does ? mean in AWS EventBridge cron?

The ? means "no specific value". Exactly one of day-of-month or day-of-week must be ?. If you schedule by weekday, set day-of-month to ?. If you schedule by date, set day-of-week to ?.

Does AWS EventBridge cron use UTC?

EventBridge Rules always interpret cron in UTC. EventBridge Scheduler can use UTC or a timezone you specify. This tool previews next runs in UTC.

What is an AWS rate expression?

A rate expression is a simpler alternative for fixed intervals: rate(value unit). Units are minute(s), hour(s), or day(s). Example: rate(5 minutes). Use singular when value is 1: rate(1 hour).

How do I run an EventBridge rule every weekday at 6 PM UTC?

Use cron(0 18 ? * MON-FRI *). The ? in day-of-month is required because day-of-week is set. Year * means every year.

How do I schedule on the last day of every month?

Use cron(0 0 L * ? *). The L in day-of-month means the last day. Day-of-week must be ?.

What does L, W, and # mean in AWS cron?

L = last day or last weekday (6L = last Friday). W = nearest weekday (15W). # = nth weekday (3#2 = second Tuesday). These are not available in Linux crontab.

Can I use a 5-field Linux cron expression in EventBridge?

No. Convert by wrapping in cron(...), adding a year field (usually *), and putting ? in one day field. Example: 0 9 * * 1-5 becomes cron(0 9 ? * MON-FRI *).

Where do I use AWS EventBridge cron expressions?

In EventBridge Rules, EventBridge Scheduler, Lambda schedules, Terraform (aws_cloudwatch_event_rule / aws_scheduler_schedule), CloudFormation, CDK, and the AWS Console schedule editor.

Is AWS EventBridge cron the same as Quartz cron?

They are similar (both use ?, L, W, # and 1-7 weekdays), but AWS has no seconds field and requires year. Quartz is second-minute-hour-... with optional year. Use our Quartz Scheduler tool for Java/Spring schedules.