example
LocalDateTime localDateTime = LocalDateTime.now();
System.out.println("localDateTime :" + localDateTime);
System.out.println("localDateTime.truncatedTo(ChronoUnit.DAYS) :" + localDateTime.truncatedTo(ChronoUnit.DAYS));
System.out.println("localDateTime.truncatedTo(ChronoUnit.HOURS) :" + localDateTime.truncatedTo(ChronoUnit.HOURS));
System.out.println("localDateTime.truncatedTo(ChronoUnit.MINUTES):" + localDateTime.truncatedTo(ChronoUnit.MINUTES));
System.out.println("localDateTime.truncatedTo(ChronoUnit.SECONDS):" + localDateTime.truncatedTo(ChronoUnit.SECONDS));
System.out.println("localDateTime.truncatedTo(ChronoUnit.MILLIS) :" + localDateTime.truncatedTo(ChronoUnit.MILLIS));