timezones: picker lists Europe/Kiev instead of Europe/Kyiv

[Mark-Life]

Labels: 🐛 bug, bookings, i18n

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Problem:

The timezone picker in the Companion app offers Europe/Kiev. Kyiv is the Ukrainian transliteration and has been the canonical IANA name since tzdata 2022b, where Europe/Kiev was demoted to a backward-compatibility link. Showing the old Russian-derived spelling to Ukrainian users is the same class of problem as showing "Bombay" for Mumbai.

The label is the raw IANA id with underscores replaced, so whatever is in the constant is what the user sees.

// apps/mobile/constants/timezones.ts:336
  "Europe/Kiev",

The constant is a copy of packages/lib/timeZones.ts in this repo, which has the same entry at line 337. So the web app carries the same stale name and any fix should land in both lists.

Line numbers are against calcom/companion at 8ee5b15 and calcom/cal.com at main on 2026-09-28.

Reproduction:

Needs the Companion iOS app signed in to any account with a schedule.

1. Open Availability, pick a schedule, tap Edit.
2. Tap the Timezone selector.
3. Scroll to the Europe section.
4. The entry between Europe/Kaliningrad and Europe/Kirov reads Europe/Kiev.

Expected vs actual:

Expected: the picker lists Europe/Kyiv, and an account already saved with Europe/Kiev still resolves to the same zone.

Actual: the picker lists Europe/Kiev on both mobile and web, and Europe/Kyiv does not appear at all.

Proposed solution:

Rename the entry to Europe/Kyiv in both lists. Existing users stored with Europe/Kiev keep working since dayjs and the browser resolve the link, but the picker's selected-label lookup (TIMEZONES.find(tz => tz.id === timezone)) will miss and fall back to the raw stored id until they re-select. Worth checking Asia/Saigon and Asia/Rangoon at the same time, since both lists still carry those pre-rename ids too.

[ANUBHAVSINGH30]

I'd like to take this. I'll rename Europe/Kiev to Europe/Kyiv in packages/lib/timeZones.ts and check where else the old id is referenced so existing saved timezones don't break.

[mgarcialeniolabs]

I'll work on this.

[kaviraja2006]

Timezone Picker — Update Deprecated IANA Timezone Names

Issue Summary

The timezone picker currently displays the obsolete Europe/Kiev timezone instead of the current IANA standard Europe/Kyiv.

This change was introduced in tzdata 2022b, where Europe/Kiev became a backward-compatibility alias for Europe/Kyiv.

There are also other deprecated timezone identifiers, such as:

• Asia/Saigon → Asia/Ho_Chi_Minh

• Asia/Rangoon → Asia/Yangon

Updating these identifiers will keep the timezone picker aligned with the current IANA timezone database standards.

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Best Approach to Fix This

1. Identify All Files Needing Changes

Based on the code search, the timezone lists are located in:

File | Purpose | Location -- | -- | -- packages/lib/timeZones.ts | Main timezone list used by the web app | Line ~337 apps/mobile/constants/timezones.ts | Timezone list used by the Companion mobile app | Line ~336

This keeps the UI aligned with current timezone naming conventions while keeping the implementation small and low-risk.