// convert string date/time field to a long
// milliseconds "timestamp" value
String format = "yyyy:MM:dd:HH:mm:ss.SSS";
DateParser parser = new DateParser( new Fields( "ts" ), format );

pipe = new Each( pipe, new Fields( "datetime" ), parser, Fields.ALL );

// convert a long milliseconds "timestamp" value to a string
String format = "HH:mm:ss.SSS";
DateFormatter formatter =
  new DateFormatter( new Fields( "datetime" ), format );

pipe = new Each( pipe, new Fields( "ts" ), formatter, Fields.ALL );