指定範囲内の日付をランダムに取得

rand_date.groovy

@Grab(group='joda-time', module='joda-time', version='*')
import org.joda.time.*

//def rand_date(def fr, def to) { // java...
def rand_date = {fr,to->          // groovy!!
  def d = new DateTime(fr)
  def range = Days.daysBetween(d, new DateTime(to)).getDays() + 1
  d.plusDays((Integer)Math.floor(Math.random() * range)).toString("yyyy-MM-dd")
}

5.times {
  println rand_date("1978-09-30","2011-10-10")
}