cdm/src/main/java/ucar/nc2/units/TimeUnit.java
public Date add( Date d) {
    Calendar cal = Calendar.getInstance();
    cal.setTime( d);
    cal.add( Calendar.SECOND, (int) getValueInSeconds());
    return cal.getTime();
  }
public Date add( Date d) {
    Calendar cal = Calendar.getInstance();
    cal.setTime( d);
    cal.add( Calendar.SECOND, (int) getValueInSeconds());
    return cal.getTime();
  }
Add the time amount to the given Date, return a new Date.
@param d add to this Date
@return Date with getValueInSeconds() added to it.