code: public String format(Calendar calendar) {
      // As the relative period is calculated on epoch (timeInMillis), no TimeZone information is needed
      Calendar smscCalendar = Calendar.getInstance();
      return format(calendar, smscCalendar);
    }
docs: Return the relative time against current (SMSC) datetime.
  
  @param calendar the datetime.
  @return The relative time between the calendar date and the SMSC calendar date.