Need to schedule a job every hour in jenkins

Jenkins use cron expression as explained here

To schedule every hour, then you can put

0 * * * *

Then your job will be executed every hour (07:00, 08:00, 09:00 and so on)

UPDATE

As explanation on your original configuration, syntax

* */1 * * *

will executed job every minutes.

UPDATE 2

As requested in the comment, here syntax for schedule it every 3 hours

0 */3 * * *

The syntax */n means the jobs will scheduled every n hours

Jenkins suggests this way:

H * * * *

I know this is an old thread but I'm answering because apparently people still land here.

The top answer shouldn't be used anymore.

Jenkins introduced a value H.

This field follows the syntax of cron (with minor differences). Specifically, each line consists of 5 fields separated by TAB or whitespace:

MINUTE HOUR DOM MONTH DOW

• MINUTE Minutes within the hour (0–59)
• HOUR The hour of the day (0–23)
• DOM The day of the month (1–31)
• MONTH The month (1–12)
• DOW The day of the week (0–7) where 0 and 7 are Sunday.

To specify multiple values for one field, the following operators are available. In the order of precedence,

• * specifies all valid values
• M-N specifies a range of values
• M-N/X or */X steps by intervals of X through the specified range or whole valid range
• A,B,...,Z enumerates multiple values

To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible. For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.

The H symbol can be used with a range. For example, H H(0-7) * * * means some time between 12:00 AM (midnight) to 7:59 AM. You can also use step intervals with H, with or without ranges.

The H symbol can be thought of as a random value over a range, but it actually is a hash of the job name, not a random function, so that the value remains stable for any given project.

Beware that for the day of month field, short cycles such as */3 or H/3 will not work consistently near the end of most months, due to variable month lengths. For example, */3 will run on the 1st, 4th, …31st days of a long month, then again the next day of the next month. Hashes are always chosen in the 1-28 range, so H/3 will produce a gap between runs of between 3 and 6 days at the end of a month. (Longer cycles will also have inconsistent lengths but the effect may be relatively less noticeable.)

So the correct answer for building once an hour is

H * * * *

for every 3 hours

H H/3 * * *

The difference between * and H could be also explained as

• * translates to EVERY
• H translates to ANY

So e.g.

* * * * *

translates to: Build every minute, every hour, every day of month, every month, doesn't matter what day of week it is.

H * * * *

translates to: Build once every hour (x), doesn't matter what exact minute it is (can be any minute between x:00 and x:59)

H H * * *

translates to: Build once every day, doesn't matter what time it is (can be any minute and any hour between 00:00 and 23:59)

The reason why you should prefer using H instead of hardcoded time values is also explained as before

If you have 100 jobs configured with

0 0 * * *

they all will try to start at the same time causing for example a lot of poll and pull traffic at midnight.

If you have them instead all configured with

H H * * *

they all will be built once a day but not all at the same time but distributed over the day.

Schedule time range

You can than plan the schdedule better by using the time ranges e.g.

H H(18-23) * * *

All jobs will be built every day at any time between 18:00 and 23:59.

Schedule time range crossing midnight

It is even also possible to schedule jobs crossing midnight e.g. to build between 19:00pm and 5:00am.

But since cron usually doesn't allow this you can use a trick using a shiftet timezone.

E.g. I'm living in the timezone MEZ which is GMT+1 and I want to build all jobs between 19:00pm and 5:00am. In order to do that I shift my complete timezone by 5 hours using

TZ=Etc/GMT+6

Than I use a shiftet range for the hours starting at 14:00 (-> +5 = 19:00pm) and ending at 23:59 (-> +5 = 4:59am)

H H(14-23) * * *