Cron expression `15 * 28 MAY 1-5` runs at 15 minutes past the hour, on day 28 of the month, Monday through Friday, only in May

Read more in the dedicated guide: Cron weekdays (Mon-Fri).

What this cron means, field by field

Each field of 15 * 28 MAY 1-5 controls one dimension of the schedule. Hover over any value in the editor above to see its tooltip; the table below summarises the same information.

Field	Value	Means	Range / hint
minute	`15`	at minute 15	0-59. The minute(s) of the hour the job will fire.
hour	`*`	every value (wildcard)	0-23. The hour(s) of the day the job will fire (0 = midnight, 23 = 11 PM).
day of month	`28`	at day of month 28	1-31. The day(s) of the month. Use * if you want every day.
month	`MAY`	at month MAY	1-12 or JAN-DEC. The month(s). Use * for every month.
day of week	`1-5`	from day of week 1 through 5	0-7 or SUN-SAT (0 and 7 both mean Sunday). Use * for every day of the week.

Next 5 runs

Shown in UTC. Change the timezone in the editor.

Next runs · UTC

Mon 3 May · 00:15in 228d 11h
Mon 3 May · 01:15
Mon 3 May · 02:15
Mon 3 May · 03:15
Mon 3 May · 04:15

Similar cron expressions

Common variations and tweaks of 15 * 28 MAY 1-5.

Where else this cron could be used

The same expression 15 * 28 MAY 1-5 works in:

Standard Unix crontab (5-field syntax).
AWS EventBridge / Lambda Scheduled (with a 6th field for year, often *).
Vercel cron jobs (declared in vercel.json).
Quartz Scheduler and node-cron, robfig/cron and similar libraries.

Examples

0 18 * * *
Every day at 18:00
0 */5 * * *
Every 5 hours
0 18 * * 1-5
Weekdays at 18:00
0 0 1 * *
Once a month, on the 1st at midnight

Cheatsheet

Full cheatsheet

Field	Req.	Range	Wildcards
minute	yes	0-59	, - * /
hour	yes	0-23	, - * /
day of month	yes	1-31	, - * /
month	yes	1-12 or JAN-DEC	, - * /
day of week	yes	0-6 or names; some dialects use 0-7 or 1-7 — see Dialects	, - * /

Frequently asked questions

What does the cron expression `15 * 28 MAY 1-5` mean?

at 15 minutes past the hour, every hour, on day 28 of the month, Monday through Friday, only in May.

When does `15 * 28 MAY 1-5` run next?

The next runs (UTC): 2027-05-03 00:15; 2027-05-03 01:15; 2027-05-03 02:15; 2027-05-03 03:15; 2027-05-03 04:15.

Is `15 * 28 MAY 1-5` a valid cron expression?

Yes - CronTool's parser accepts this expression and the calendar projects future runs successfully.