OCP Date, Time, and Localization 2

Question 1

Which Java class should you use to represent a single point in time as seconds since the Unix epoch?

Accepted Answer

Instant

Answer

LocalDateTime

Answer

ZonedDateTime

Answer

Timestamp

Question 2

What is the result of `LocalDate.of(2024, 1, 31).plusMonths(1)`?

Accepted Answer

2024-02-29

Answer

2024-02-28

Answer

A DateTimeException is thrown

Answer

2024-03-02

Question 3

Which expression correctly calculates the total number of days between two LocalDate instances?

Accepted Answer

ChronoUnit.DAYS.between(date1, date2)

Answer

Period.between(date1, date2).getDays()

Answer

Duration.between(date1, date2).toDays()

Answer

date1.until(date2)

Question 4

How do you convert a ZonedDateTime to the same instant in a different time zone?

Accepted Answer

zonedDateTime.withZoneSameInstant(ZoneId.of("Europe/London"))

Answer

zonedDateTime.toZone(ZoneId.of("Europe/London"))

Answer

ZonedDateTime.of(zonedDateTime, ZoneId.of("Europe/London"))

Answer

zonedDateTime.atZone(ZoneId.of("Europe/London"))

Question 5

What is the output of `DateTimeFormatter.ofPattern("MM/dd/uuuu").format(LocalDate.of(2024, 6, 5))`?

Accepted Answer

"06/05/2024"

Answer

"6/5/2024"

Answer

"06/5/2024"

Answer

"6/05/2024"

Question 6

Which statement about the zone ID "US/Eastern" is correct?

Accepted Answer

It is a valid alias for America/New_York and handles DST automatically

Answer

It throws a ZoneRulesException because the format is invalid

Answer

It creates a fixed offset without DST adjustment

Answer

It is not recognized by Java's built-in zone database

Question 7

What is the key difference between ZonedDateTime and OffsetDateTime?

Accepted Answer

ZonedDateTime includes DST rules tied to a geographic zone; OffsetDateTime stores a fixed UTC offset only

Answer

OffsetDateTime is more precise because it stores nanoseconds

Answer

ZonedDateTime can only represent UTC times

Answer

OffsetDateTime automatically adjusts for daylight saving transitions