Question 274 of 513
Duration Class Overview
Which TWO statements are true about the java.time.Duration class? (Choose two.)
Quick Answer
The correct answer is that Duration can be negative. This is because the java.time.Duration class models a time-based amount of time in seconds and nanoseconds, representing quantities like hours, minutes, and seconds, and unlike Period, it is not tied to calendar dates—so a negative duration simply indicates a time interval going backward. On the Oracle Certified Professional Java SE 17 Developer 1Z0-829 exam, this concept tests your understanding of the Duration class overview and its properties, often appearing in questions that try to confuse Duration with Period or with the assumption that time amounts must always be positive. A common trap is thinking Duration only stores positive values, but the API explicitly allows negative values to represent elapsed time in reverse. Memory tip: think of a stopwatch that can count down as well as up—Duration handles both directions.
⚠ Common exam trap
Many exam-takers confuse Duration with Period, mistakenly thinking Duration can handle days, months, or daylight-saving adjustments, or that Duration.between() works with any temporal type like LocalDate.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Duration represents a time-based amount of time, such as hours, minutes, seconds.
The java.time.Duration class models a time-based amount of time in terms of seconds and nanoseconds, which can represent hours, minutes, seconds, and smaller units. It is designed for time-based quantities, not date-based ones like days, months, or years.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Duration represents a time-based amount of time, such as hours, minutes, seconds.
Why this is correct
Duration is based on seconds/nanoseconds.
- ✗
Duration.ofDays(1) returns a Duration that is daylight-saving-safe.
Why it's wrong here
Duration is fixed 24 hours, not DST-aware.
- ✗
Duration.between(LocalDate.now(), LocalDate.now().plusDays(1)) returns a Duration of 1 day.
Why it's wrong here
Duration.between requires temporals that support seconds; LocalDate does not.
- ✗
Duration can represent a period of months.
Why it's wrong here
Period represents months, not Duration.
- ✓
Duration can be negative.
Why this is correct
Duration can be negative.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on 1Z0-829
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which two statements about the java.time.Duration class are true? (Choose two.)
medium- A.Duration supports units like months and years.
- ✓ B.Duration can be negative.
- ✓ C.Duration is immutable and thread-safe.
- D.Duration.between(LocalDate.now(), LocalDate.now()) returns a Duration.
- E.Duration uses a days-based representation.
Why B: The java.time.Duration class can represent negative durations, such as when the end instant is before the start instant in a Duration.between() call. Option C is correct because all classes in the java.time package, including Duration, are immutable and thread-safe by design, ensuring safe concurrent access without synchronization.
Last reviewed: Jun 11, 2026
This 1Z0-829 practice question is part of Courseiva's free Oracle certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 1Z0-829 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.