fix(date): resolve timezone issues in DatePrompt

[harshaktg]

Description

Fixes timezone-related test failures in DatePrompt where dates were off by one day when running tests in timezones east of UTC (e.g., UTC+05:30).

Problem

When running tests in UTC+05:30 (IST), 5 tests in the core package and 12 tests in the prompts package were failing because:

• Dates were being created at local midnight using new Date(year, month, day)
• When converted to ISO strings via .toISOString(), JavaScript converts to UTC
• This caused dates to shift backward by one day in timezones ahead of UTC

Example:

• new Date(2025, 0, 15) creates 2025-01-15 00:00:00 in local time (UTC+05:30)
• Converting to UTC: 2025-01-14 18:30:00 UTC
• .toISOString().slice(0, 10) returns '2025-01-14' ❌ (expected '2025-01-15')

Solution

Updated all date operations in DatePrompt to consistently use UTC:

• dateToSegmentValues(): Changed to use getUTCFullYear(), getUTCMonth(), getUTCDate()
• segmentValuesToParts(): Changed to use Date.UTC() for date validation
• segmentValuesToDate(): Changed to create dates using Date.UTC()
• Test helpers: Updated d() helper functions in both test files to use Date.UTC()

Testing

• ✅ All 96 core package tests pass
• ✅ All 534 prompts package tests pass (630 total)
• ✅ Tested in UTC+05:30 timezone where the bug was originally discovered
• ✅ Linting, formatting, and type checking all pass

Files Changed

• packages/core/src/prompts/date.ts
• packages/core/test/prompts/date.test.ts
• packages/prompts/test/date.test.ts

Before

After

[changeset-bot]

🦋 Changeset detected

Latest commit: 3b1d83e

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@clack/prompts	Patch
@clack/core	Patch

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[dreyfus92]

hey @harshaktg thank you for fixing this, looks good overall just left a tiny nit 😄

[dreyfus92]

Thanks again @harshaktg 💜