British Columbia, Time Zones, and Postgres

British Columbia's 2026 move to permanent Pacific Daylight Saving Time (UTC-7 year-round) creates a significant risk for PostgreSQL databases: appointments stored using `timestamptz` columns before the timezone rule update may display one hour off after the `tzdata` package updates, since these columns store UTC time and convert based on current rules rather than the original input values. To avoid this problem, the article recommends adopting a dual-column storage pattern that explicitly stores both local timestamp and timezone alongside UTC values, ensuring appointments remain accurate even when timezone rules change.