Glossary

Timezone drift

When calendar events shift by an hour or a day because timezone rules were ignored or misapplied.

Drift shows up as practices an hour off after daylight saving changes, or all-day events bleeding into the previous day for faraway viewers. The root causes are storing wall time without timezone context or publishing feeds without VTIMEZONE rules.

The cure is boring correctness: store instants in UTC, keep the calendar's IANA timezone, emit VTIMEZONE in feeds, and encode all-day events as floating dates.