DEV Community

DevCorner2
DevCorner2

Posted on

📅 Mastering Java Date and Time API: LocalDate, LocalTime, LocalDateTime, and ZonedDateTime

Java 8 introduced a modern java.time package that replaces the old Date and Calendar classes. This blog post will walk you through the most commonly used classes: LocalDate, LocalTime, LocalDateTime, and ZonedDateTime, along with practical examples.

✅ 1. LocalDate – Date Only (No Time or Zone)

LocalDate is used to represent a date without time or timezone, like 2025-05-21.

Example: LocalDate in Action 

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

public class LocalDateExample {
    public static void main(String[] args) {
        // Current date
        LocalDate today = LocalDate.now();
        System.out.println("Today: " + today);

        // Specific date
        LocalDate independenceDay = LocalDate.of(2025, 7, 4);
        System.out.println("Independence Day: " + independenceDay);

        // Parse from string
        LocalDate parsed = LocalDate.parse("2025-12-25");
        System.out.println("Parsed Date: " + parsed);

        // Formatting
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MMM uuuu");
        System.out.println("Formatted: " + today.format(formatter));

        // Date arithmetic
        LocalDate nextWeek = today.plusWeeks(1);
        System.out.println("One week later: " + nextWeek);
    }
}
Enter fullscreen mode Exit fullscreen mode

⏰ 2. LocalTime – Time Only (No Date or Zone)

LocalTime is for time-only values, like 14:30:00.

Example: LocalTime in Action 

import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

public class LocalTimeExample {
    public static void main(String[] args) {
        // Current time
        LocalTime now = LocalTime.now();
        System.out.println("Now: " + now);

        // Specific time
        LocalTime lunchTime = LocalTime.of(12, 30);
        System.out.println("Lunch time: " + lunchTime);

        // Parse from string
        LocalTime parsed = LocalTime.parse("18:45:00");
        System.out.println("Parsed Time: " + parsed);

        // Formatting
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("hh:mm a");
        System.out.println("Formatted: " + now.format(formatter));

        // Time arithmetic
        LocalTime plusHour = now.plusHours(1);
        System.out.println("One hour later: " + plusHour);
    }
}
Enter fullscreen mode Exit fullscreen mode

🕒 3. LocalDateTime – Date and Time (No Zone)

LocalDateTime combines date and time, useful for timestamps without zone handling.

Example: LocalDateTime in Action 

import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

public class LocalDateTimeExample {
    public static void main(String[] args) {
        // Current date-time
        LocalDateTime now = LocalDateTime.now();
        System.out.println("Now: " + now);

        // Specific date-time
        LocalDateTime meeting = LocalDateTime.of(2025, 5, 21, 14, 0);
        System.out.println("Meeting: " + meeting);

        // Parse from string
        LocalDateTime parsed = LocalDateTime.parse("2025-08-15T10:15:30");
        System.out.println("Parsed DateTime: " + parsed);

        // Formatting
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MMM uuuu, hh:mm a");
        System.out.println("Formatted: " + now.format(formatter));

        // Date-time arithmetic
        LocalDateTime tomorrowSameTime = now.plusDays(1);
        System.out.println("Same time tomorrow: " + tomorrowSameTime);
    }
}
Enter fullscreen mode Exit fullscreen mode

🌐 4. ZonedDateTime – Date and Time with Zone

ZonedDateTime includes zone and offset information. This is vital for global applications.

Example: ZonedDateTime in Action 

import java.time.ZonedDateTime;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;

public class ZonedDateTimeExample {
    public static void main(String[] args) {
        // Current date-time with system zone
        ZonedDateTime now = ZonedDateTime.now();
        System.out.println("Now (default zone): " + now);

        // Specific zone
        ZoneId parisZone = ZoneId.of("Europe/Paris");
        ZonedDateTime parisTime = ZonedDateTime.now(parisZone);
        System.out.println("Paris time: " + parisTime);

        // From LocalDateTime + Zone
        ZonedDateTime meetingInNY = ZonedDateTime.of(
            2025, 12, 31, 23, 59, 0, 0,
            ZoneId.of("America/New_York")
        );
        System.out.println("NYE meeting in NY: " + meetingInNY);

        // Parsing with zone
        ZonedDateTime parsed = ZonedDateTime.parse("2025-07-01T12:00:00+02:00[Europe/Paris]");
        System.out.println("Parsed ZonedDateTime: " + parsed);

        // Formatting
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd MMM uuuu HH:mm z");
        System.out.println("Formatted Paris time: " + parisTime.format(formatter));

        // Zone conversion
        ZonedDateTime inTokyo = parisTime.withZoneSameInstant(ZoneId.of("Asia/Tokyo"));
        System.out.println("Same instant in Tokyo: " + inTokyo);
    }
}
Enter fullscreen mode Exit fullscreen mode

🧠 Final Thoughts

  • Use LocalDate and LocalTime for simple calendar and clock tasks.
  • Use LocalDateTime for timestamps without needing time zone handling.
  • Use ZonedDateTime when you need to track events across different regions of the world.
  • All classes in java.time are immutable and thread-safe.

Top comments (0)