Proton Account already has the right foundation: account settings are shared across all Proton services, and some regional settings exist. Mail offers default language, time zone and date/time format under Language and time. Calendar offers week start day, week number display, time zone with a secondary time zone, and subscribable public holiday calendars. But the settings are incomplete, inconsistent across products, and not composable: language is a single dropdown with no English variants (en-GB, en-AU, en-CA, en-IN, en-ZA and others), and most regional settings (measurement units, temperature, currency, number formatting, financial years, paper sizes) exist nowhere in the ecosystem.

This request: one regional settings framework, held at Proton Account level, completing the settings that partially exist and consolidating them so they apply consistently. Each setting offers two modes: applied to all apps linked to the account, or overridden per app. Not every setting applies to every product, so each appears only where relevant. Examples below are illustrative, not exhaustive: the request is coverage of formats in use by everyone in every country globally, with custom options catching the remainder.

1. English variants with full spelling, grammar and punctuation rules: applies to Mail, Calendar, Drive, Docs, Sheets, Meet and Lumo wherever text is generated or assisted.

2. Date format (DD/MM/YYYY, MM/DD/YYYY, ISO YYYY-MM-DD, YYYY/MM/DD, D.M.YYYY) and alternative calendars (Islamic Hijri, Hebrew, Japanese era, Thai Buddhist, Persian Solar Hijri, Indian Saka, among others): applies to Mail timestamps and quoted replies, Calendar views and exports, Drive file dates, Docs, Sheets and Lumo. Prevents 09/01/2026 being read as two different dates eight months apart.

3. Week start day and week numbering: already in Calendar; extend to Docs, Sheets and Lumo when they generate schedules, sourced from one account setting.

4. Clock format (24h or 12h) and time zone handling, including fractional offsets (UTC+5:30 India, UTC+5:45 Nepal, UTC+12:45 Chatham Islands): applies to Mail, Calendar, Meet and Lumo. One related privacy gap worth fixing alongside: Mail's quoted replies currently use the local time zone, which leaks location to the correspondent, as documented in the existing Set timezone suggestion on this forum. A user-configured time zone, used consistently, closes this.

5. Holiday calendars: already in Calendar with per-calendar language editing; extend to include religious observances across every major tradition, school terms by jurisdiction, and multi-calendar subscription for users spanning several countries, and surface them in Lumo scheduling assistance.

6. Measurement units and temperature scale (Celsius/Fahrenheit independent of metric/imperial): Docs, Sheets, Lumo and Drive previews.

7. Currency as default display currency: Lumo, Sheets and Docs, so financial discussion does not assume USD, with conversion on request only.

8. Number formatting (1,234.56 versus 1.234,56 versus thin space versus Swiss apostrophe, Indian lakh and crore grouping, Arabic-Indic numerals): Sheets cell formatting and formula parsing, Docs, Lumo and Wallet balances. The same number in the wrong convention is actively misread.

9. Financial year conventions (calendar year, 1 July to 30 June Australia and New Zealand, 1 April to 31 March India and Japan, 6 April to 5 April UK personal tax, 1 October to 30 September US federal, plus a custom start date): Calendar views, Sheets templates and Lumo budgeting assistance.

10. Paper size defaults (ISO A and B series, US Letter and Legal, JIS and traditional Japanese sizes, ANSI, Latin American formats): Docs, Sheets and Lumo document generation and printing advice.

11. Cultural reference conventions and academic citation styles (Harvard, APA, MLA, Chicago, Oxford): Lumo and Docs, so examples and referencing are region-appropriate rather than US defaults.

Implementation: settings managed at account level, synced across web and mobile, per-app override as the exception so defaults propagate. The settings already exist piecemeal (language and time in Mail, week start and holidays in Calendar); the request is to complete the set and unify it. Apple's Language and Region settings prove this granularity is feasible at operating-system level. No privacy-focused competitor suite offers it ecosystem-wide. Proton would be the first.

With over 100 million Proton users around the world, a single regional default cannot serve everyone fairly. These settings would make Proton truly global in practice, not just in name. If you read this far, thank you, please vote in support if you would like to see these added, and thank you to the team at Proton.