get prev day

getpreviousday.scala

    Given a date like 2015-12-31, obtain 2015-12-30
    */
    def getPreviousDay(mydate:String):String = {
        val fmt = new SimpleDateFormat("yyyy-MM-dd")
        val date = fmt.parse(mydate)
        val cal = Calendar.getInstance
        cal.setTime(date)
        cal.add(Calendar.DAY_OF_MONTH,-1)
        fmt.format(cal.getTime)
    }