Jenkins groovy script to print scheduling rules for all the jobs

gistfile1.groovy

import hudson.triggers.*;

for (item in Jenkins.instance.getItems(Project)) {
    println("--- Scheduling for " + item.name + " ---")
    def trigger = item.triggers.get(Jenkins.instance.getDescriptor(TimerTrigger.class));
    if (trigger) {
        println trigger.spec;
    }
}