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Code Completion 8 Challenges

JavaScript Dates and Modern Time with Temporal — Code Completion

Practice the core Date and Temporal APIs.

Challenge 1

Read the epoch time value

javascript Your answer 
const date = new Date(0);
const value = date.();
console.log(value);

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Challenge 2

Produce an ISO UTC string

javascript Your answer 
const date = new Date("2026-09-27T12:00:00Z");
console.log(date.());

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Challenge 3

Create a UTC time value

javascript Your answer 
const value = Date.(2026, 8, 27);
console.log(new Date(value).toISOString());

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Challenge 4

Detect an invalid Date

javascript Your answer 
const date = new Date("nope");
const valid = Number.(date.getTime());
console.log(valid);

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Challenge 5

Create a Temporal instant

javascript Your answer 
const instant = Temporal.("2026-09-27T12:00:00Z");
console.log(instant.toString());

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Challenge 6

Create a calendar date

javascript Your answer 
const date = Temporal.("2026-09-27");
console.log(date.toString());

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Challenge 7

Return a new Temporal date one day later

javascript Your answer 
const date = Temporal.PlainDate.from("2026-09-27");
const next = date.({ days: 1 });
console.log(next.toString());

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Challenge 8

Create a duration

javascript Your answer 
const duration = Temporal.({ hours: 3, minutes: 30 });
console.log(duration.toString());

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