Journal Day Lifecycle

Timezone-aware Journal logical-day windows, boundary policy, DST handling, and safe transitions.

Details

Journal today is the active logical Journal day, not necessarily the current civil date.

Policy

The active policy contains an IANA timezone and a local boundary time. An instant belongs to the half-open window [start, end) for one logical date. The backend resolves that date and returns aware start/end instants to UI and downstream consumers.

The built-in default boundary is 05:00, but it is a configurable Journal policy rather than a universal invariant.

Callers must not compute the end by adding 24 hours. Day length can differ around daylight-saving transitions, and browser or host timezone inference can disagree with Work Buddy's configured timezone.

DST behavior

Local boundary construction resolves gaps and folds explicitly. A nonexistent wall time advances to the first valid instant. An ambiguous wall time uses the policy's deterministic fold rule. The resulting adjacent windows remain contiguous and non-overlapping.

Policy changes

Changing the boundary creates a pending transition that becomes effective at the next safe day boundary. Policy epochs retain the timezone, boundary, and effective range under which days were created. Existing Journal days are not silently reassigned to a different window.

journal_state exposes logical date, timezone, boundary, window start/end, and policy transition metadata. UI surfaces display those values rather than hardcoding one user's boundary or timezone.

The configured logical-day policy replaces early-morning prompts that ask whether the user means today or yesterday. Explicit date targets remain explicit.

See journal/journal_state, settings, and services/dashboard/react/calendar-surface.