Date & Time API - Quiz

Create a LocalDate for 2023-10-01 to represent a due date in a task manager

Measure how many days are between two LocalDate values for a subscription period

Format a LocalDateTime using a reusable formatter before logging it

Which statement about the Java 8 Date & Time API classes like LocalDate and LocalTime is TRUE?

What does LocalDate represent in the Java Date & Time API?

Which method gets the current LocalTime using the system clock?

Which class should you use to represent a moment on the UTC timeline for logging events?

You need to schedule a meeting for "2025-03-10T09:00" in Europe/Berlin. Which class best represents this?

Which type is best for representing a 3-day vacation length, independent of start date?

Which DateTimeFormatter is predefined for a standard ISO local date like 2025-01-31?

How do DateTimeFormatter patterns treat 'MM' and 'mm'?

What does ChronoUnit.DAYS.between(start, end) return when used with two LocalDate values?

Which approach converts a LocalDateTime to a specific time zone-aware value?

Which statement about Duration and Period is TRUE?

Order the steps to create a ZonedDateTime from the current local date-time in a specific zone and then format it for display.

Drag and drop to reorder, or use the arrows.

Order the steps to measure a task's running time using Instant and Duration.

Drag and drop to reorder, or use the arrows.

What is the output of this code that calculates days between two dates?

1import java.time.*;
2import java.time.temporal.ChronoUnit;
3
4public class Main {
5    public static void main(String[] args) {
6        LocalDate start = LocalDate.of(2024, 1, 1);
7        LocalDate end = LocalDate.of(2024, 1, 10);
8        long days = ChronoUnit.DAYS.between(start, end);
9        System.out.println(days);
10    }
11}

What does this code print when adding a Period to a LocalDate?

1import java.time.*;
2
3public class Main {
4    public static void main(String[] args) {
5        LocalDate date = LocalDate.of(2023, 12, 31);
6        Period period = Period.ofDays(1);
7        LocalDate result = date.plus(period);
8        System.out.println(result);
9    }
10}

What is the output when formatting a LocalTime?

1import java.time.*;
2import java.time.format.*;
3
4public class Main {
5    public static void main(String[] args) {
6        LocalTime time = LocalTime.of(9, 5);
7        DateTimeFormatter f = DateTimeFormatter.ofPattern("HH:mm");
8        System.out.println(time.format(f));
9    }
10}

What does this code print when converting a LocalDateTime to an Instant in UTC?

1import java.time.*;
2
3public class Main {
4    public static void main(String[] args) {
5        LocalDateTime ldt = LocalDateTime.of(2020, 1, 1, 0, 0);
6        ZonedDateTime zdt = ldt.atZone(ZoneId.of("UTC"));
7        Instant instant = zdt.toInstant();
8        System.out.println(instant); 
9    }
10}

What is printed when computing a Duration in minutes between two times?

1import java.time.*;
2
3public class Main {
4    public static void main(String[] args) {
5        LocalTime start = LocalTime.of(10, 0);
6        LocalTime end = LocalTime.of(11, 30);
7        long minutes = Duration.between(start, end).toMinutes();
8        System.out.println(minutes);
9    }
10}

Find the bug in this code that parses a date string and prints it.

Click on the line(s) that contain the bug.

import java.time.*;

import java.time.format.*;

public class Main {

    public static void main(String[] args) {

        String text = "31-01-2024";

        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd");

        LocalDate date = LocalDate.parse(text, formatter);

        System.out.println(date);

    }

}

Find the bug in this code that tries to create a Duration between two LocalDate values.

Click on the line(s) that contain the bug.

import java.time.*;

public class Main {

    public static void main(String[] args) {

        LocalDate start = LocalDate.of(2024, 1, 1);

        LocalDate end = LocalDate.of(2024, 1, 5);

        Duration d = Duration.between(start, end);

        System.out.println(d.toDays());

    }

}

Match each date-time class with its most appropriate description.

Click an item on the left, then click its match on the right. Click a matched item to unmatch.

Match the Date & Time API concepts with their typical use cases.

Click an item on the left, then click its match on the right. Click a matched item to unmatch.

Complete the code to create a LocalDateTime from separate LocalDate and LocalTime objects and format it using a custom pattern.

Complete the code to add a one-week Period to a LocalDate and print the result.

Complete the code to obtain the current time in a specific zone and convert it to another zone.

Complete the code to parse a date string with ISO_LOCAL_DATE and then print the next day.

Click the line that applies the DateTimeFormatter to format the LocalDate.

Click on the line to select.

import java.time.*;

import java.time.format.*;

public class Main {

    public static void main(String[] args) {

        LocalDate today = LocalDate.now();

        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy");

        String text = today.format(formatter);

        System.out.println(text);

    }

}

Click the line that converts the current moment into a ZonedDateTime using the system default zone.

Click on the line to select.

import java.time.*;

public class Main {

    public static void main(String[] args) {

        Instant now = Instant.now();

        ZoneId systemZone = ZoneId.systemDefault();

        ZonedDateTime zoned = now.atZone(systemZone);

        System.out.println(zoned);

    }

}