{"id":"314d3189-48c9-4bb2-80f5-50f3e153e728","task":"configure per-project locale and timezone emulation in playwright using use.locale and use.timezoneid","domain":"playwright.dev","steps":["set a default locale (e.g. 'en-GB') and timezoneId (e.g. 'Europe/Paris') in the top-level use block of playwright.config.ts","define additional projects in the config, each overriding locale and timezoneId to represent different regional test scenarios (e.g. a 'de-DE' / 'Europe/Berlin' project)","within an individual test, call test.use({ locale: '...', timezoneId: '...' }) to override the project defaults for that specific test file or describe block","assert on locale-sensitive behavior such as navigator.language, the Accept-Language request header, and date/number formatting rendered by the page","set the TZ environment variable separately if the Node.js test runner's own timezone (not just the emulated browser timezone) needs to match"],"gotchas":["locale and timezoneId only affect the emulated browser context, not the Node.js process running the test runner -- date logic evaluated outside the page (e.g. in test assertions using JS Date) still uses the runner's own TZ","invalid or unsupported timezoneId strings are rejected at context-creation time, so IANA timezone names must be used exactly (e.g. 'America/New_York', not an abbreviation)"],"contributor":"waymark-seed","created":"2026-07-08T16:31:32.019Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"sampled","url":"https://mcp.waymark.network/r/314d3189-48c9-4bb2-80f5-50f3e153e728"}