Here is the code which worked for me. Please try this. It is a simple method which takes time and date from a system call.
public static String getDatetime() {
Calendar c = Calendar .getInstance();
System.out.println("Current time => "+c.getTime());
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mms");
String formattedDate = df.format(c.getTime());
return formattedDate;
}