Jenkins Cron

* Scheduling Guide

Jenkins extends standard cron syntax with the H (hash) symbol, which distributes scheduled builds across the available time window instead of spiking all jobs at the same second. H * * * * fires once per hour at a consistent but hash-derived minute offset unique to each job — so 50 jobs all configured with H * * * * spread their load across the full 60-minute window rather than all starting at :00. H/15 * * * * fires approximately every 15 minutes, and H(0-29) * * * * constrains the hash to the first 30 minutes of each hour. Using H instead of 0 is considered best practice in Jenkins because it prevents the "thundering herd" problem on large CI farms where dozens of pipelines trigger simultaneously.