Java 8 Date and Time API Tutorial with Code Examples

Java 8 introduced a modern, immutable, and thread‑safe date‑time API (java.time) that replaces the mutable java.util.Date and non‑thread‑safe SimpleDateFormat classes.

Example 1 shows how to obtain today’s date using LocalDate.now() and print it.

Example 2 extracts the year, month, and day from the current date with getYear() , getMonthValue() , and getDayOfMonth() .

Example 3 creates a custom date with LocalDate.of(2018, 2, 6) .

Example 4 compares two dates using equals() to determine if they are the same.

Example 5 uses MonthDay to check whether today matches a recurring event such as a birthday.

Example 6 obtains the current time (without a date) via LocalTime.now() .

Example 7 adds three hours to the current time with plusHours(3) .

Example 8 calculates the date one week later using plus(1, ChronoUnit.WEEKS) .

Example 9 demonstrates moving one year forward or backward with plus and minus using ChronoUnit.YEARS .

Example 10 introduces the Clock class for obtaining timestamps and system‑default zone time.

Example 11 compares dates with isAfter() and isBefore() .

Example 12 shows how to convert a local date‑time to a specific time‑zone using ZoneId and ZonedDateTime .

Example 13 uses YearMonth to represent fixed‑date concepts such as credit‑card expiry and to query the number of days in a month.

Example 14 checks for a leap year with isLeapYear() .

Example 15 calculates the number of months between today and a future date using Period.between() .

Example 16 obtains the current instant (timestamp) with Instant.now() and shows conversion to epoch milliseconds.

Example 17 parses a compact ISO date string using DateTimeFormatter.BASIC_ISO_DATE .

Example 18 demonstrates formatting a LocalDateTime to a string and parsing it back to a LocalDate with custom patterns.