1. Date to String ====================================================== Date now = new Date(); String strnow =""; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); strnow = sdf.format(now); Log.d("xxx"," strnow "+strnow); 2. String to Date ====================================================== try { Date ddate = new Date(); String strdate= "2017-09-09 11:11:11"; SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); ddate = sdf.parse(strdate); Log.d("xxx","ddate "+ddate .toString()); } catch (ParseException e) { e.printStackTrace(); } 3. SimpleDateFormat ====================================================== SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd"); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); S...