jenkins-reprocess-date-range.groovy

// ...

def endDate = new Date().clearTime() // today
def startDate = endDate - 30
def newDateParsed

startDate.upto(endDate) {
    newDateParsed = it.format("yyyy-MM-dd")
    println(newDateParsed)
    
    stage("newDateParsed ${newDateParsed}") {
        // do your stuff here
    }
}

// ...