Currently it's O(n) - we do `n` shifts of bytes within `StringBuilder`. This can be reduced to O(1) improving the code like:

DateTimeFormatter dtf = new DateTimeFormatterBuilder()
  .appendLiteral("Date:")
  .padNext(50, '\t')
  .append(DateTimeFormatter.ISO_DATE)
  .toFormatter();
String text = dtf.format(LocalDateTime.now());