The main improvements over previous classes are Thread safety and ease of use.
LocalDate
Represents a date in ISO format (yyyy-MM-dd) without time.
// Declaration
final LocalDate ld1 = LocalDate.now();
final LocalDate ld2 = LocalDate.of(2015, 02, 20);
final LocalDate ld3 = LocalDate.parse("2015-02-20");
// Add and substract units
final LocalDate today = LocalDate.now();
final LocalDate tomorrow = today.plusDays(1);
final LocalDate future = today.plus(1, ChronoUnits.CENTURIES);
final LocalDate past = today.minus(1, ChronoUnits.ERAS);
// Utility methods
final LocalDate now = LocalDate.now();
final DayOfWeek dow = now.getDayOfWeek();
final boolean isLeapYear = now.isLeapYear();
// compare days
final LocalDate yesterday = LocalDate.now().minusDays(1);
final boolean isBefore = yesterday.isBefore(now);
LocalTime
Represents a time, without date.
// Declaration
final LocalTime lt1 = LocalTime.now();
final LocalTime lt2 = LocalTime.parse("06:30");
final LocalTime lt3 = LocalTime.of(06, 30);
// Add and substract
final LocalTime future = LocalTime.now().plusHours(1);
// Utilities
final LocalTime max = LocalTime.MAX;
LocalDateTime
It’s a combination of date and time. This is the most commonly used class.
// Declaration
final LocalDateTime ldt1 = LocalDateTime.now();
final LocalDateTime ldt2 = LocalDateTime.of(2015, Month.FEBRUARY, 20, 06, 30);
final LocalDateTime ldt3 = LocalDateTime.parse("2015-02-20T06:30:00");
// It has methods from the previous 2.
final LocalDateTime future1 = ldt1.plusDays(1);
final LocalDateTime future2 = ldt1.plusHours(5);
ZonedDateTime & OffsetDateTime
Used when we need to deal with specific time zones. It uses a LocalDateTime + ZoneId for ZonedDateTime or LocalDateTime + ZoneOffset for OffsetDateTime.
// ZonedDateTime.
final LocalDateTime now = LocalDateTime.now();
final ZoneId zone = ZoneId.of("Europe/Berlin");
final ZonedDateTime zdt = ZonedDateTime.of(now, zone);
// OffsetDateTime
final ZoneOffset zo = ZoneOffset.of("+02:00");
final OffsetDateTime odt = OffsetDateTime.of(now, zo);
Period & Duration
Period represents the time in years, months and days, passed between two LocalDates
final LocalDate now = LocalDate.now();
final LocalDate future = now.plusDays(5);
final Period period = Period.between(now, future);
final int daysPassed = period.getDays();
Duration represents the time in seconds and nano-seconds from a LocalTime.
final LocalTime now = LocalTime.now();
final LocalTime past = now.minusMinutes(50);
final Duration dur = Duration.between(now, past);
final int nanos = dur.getNano();