feat(timezones): IANA timezone offset transition calculator with dayl… by Rodrigoue9 · Pull Request #30024 · calcom/cal.diy

Rodrigoue9 · 2026-08-21T18:13:18Z

…ight saving adjustments

What does this PR do?

Fixes #XXXX (GitHub issue number)

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Checklist

I haven't read the contributing guide
My code doesn't follow the style guidelines of this project
I haven't commented my code, particularly in hard-to-understand areas
I haven't checked if my changes generate no new warnings
My PR is too large (>500 lines or >10 files) and should be split into smaller PRs

…ight saving adjustments

github-actions · 2026-08-21T18:13:25Z

Welcome to Cal.diy, @Rodrigoue9! Thanks for opening this pull request.

A few things to keep in mind:

This is Cal.diy, not Cal.com. Cal.diy is a community-driven, fully open-source fork of Cal.com licensed under MIT. Your changes here will be part of Cal.diy — they will not be deployed to the Cal.com production app.
Please review our Contributing Guidelines if you haven't already.
Make sure your PR title follows the Conventional Commits format.

A maintainer will review your PR soon. Thanks for contributing!

coderabbitai · 2026-08-21T18:17:42Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Run ID: b661bcf3-5765-4468-ad3e-c216b9b31ad9

📥 Commits

Reviewing files that changed from the base of the PR and between 7365cd1 and 6ee026b.

📒 Files selected for processing (2)

packages/lib/timezone_dst_helper.test.ts
packages/lib/timezone_dst_helper.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 9 remain after this review.

📝 Walkthrough

Walkthrough

Updated getTimezoneOffsetMinutes to parse GMT offset components separately and apply the sign to the full minute total. Added documentation and expanded date formatting options. Added tests for offsets of -180, -210, and 330 minutes across three timezones.

Merge Risk: ⚪ Minimal · up to 6ee02

This PR adds a localized IANA timezone offset transition helper with daylight-saving adjustments and tests; no actionable merge-blocking risk remains after normal checks and review.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title identifies the timezone offset transition calculator and daylight saving adjustment change, which matches the main objective of the changeset.
Description check	✅ Passed	The description mentions daylight saving adjustments, which is related to the changeset. It does not provide issue details, testing instructions, demonstrations, or completed checklist items.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 1 functions across 2 files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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Actionable comments posted: 1

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Inline comments:
In `@packages/lib/timezone_dst_helper.ts`:
- Around line 3-5: Update the GMT offset parsing to capture the sign separately
and apply it to the combined hour-and-minute total, so values such as GMT-3:30
produce -210 minutes. Add a regression test covering a negative fractional
offset.

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ℹ️ Review info

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Configuration used: Organization UI

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Run ID: dc70ccea-fe15-4c88-9a8b-2934d15c45c8

📥 Commits

Reviewing files that changed from the base of the PR and between 176037d and 7365cd1.

📒 Files selected for processing (1)

packages/lib/timezone_dst_helper.ts

Included review availability: Your plan provides up to 10 included reviews per hour; 9 remain after this review.

…ion tests (calcom#30024)

… regression tests (calcom#30015, calcom#30024)

feat(timezones): IANA timezone offset transition calculator with dayl…

7365cd1

…ight saving adjustments

pull-request-size Bot added the size/XS label Aug 21, 2026

coderabbitai Bot reviewed Aug 21, 2026

View reviewed changes

Comment thread packages/lib/timezone_dst_helper.ts Outdated

Rodrigoue9 added a commit to Rodrigoue9/cal.diy that referenced this pull request Aug 22, 2026

fix(timezones): support negative fractional timezones and add regress…

b434eed

…ion tests (calcom#30024)

Rodrigoue9 added a commit to Rodrigoue9/cal.diy that referenced this pull request Aug 22, 2026

fix(i18n): clean diff, document fractional negative timezones and add…

bf95742

… regression tests (calcom#30015, calcom#30024)

fix(timezones): apply sign to fractional UTC offsets

6ee026b

pull-request-size Bot added size/M and removed size/XS labels Aug 26, 2026

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feat(timezones): IANA timezone offset transition calculator with dayl… - #30024

feat(timezones): IANA timezone offset transition calculator with dayl…#30024
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Rodrigoue9:feat/dst-timezone-transition-helper

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coderabbitai Bot commented Aug 21, 2026 •

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Rodrigoue9 commented Aug 21, 2026

What does this PR do?

Visual Demo (For contributors especially)

Video Demo (if applicable):

Image Demo (if applicable):

Mandatory Tasks (DO NOT REMOVE)

How should this be tested?

Checklist

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github-actions Bot commented Aug 21, 2026

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coderabbitai Bot commented Aug 21, 2026 •

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