The Problem with Time & Timezones - Computerphile

Caption notes

Tom Scott tells a cautionary story about a programmer receiving one more date-and-time requirement after another: offsets need not be whole hours, daylight-saving rules vary by place and date, and government decisions, historical calendars and leap seconds add different complications. The useful lesson is to treat time rules as maintained data and reuse established implementations, rather than model everything as a fixed offset. This is a historical explanation, not a current technical specification for the country rules, calendar dates, standards bodies or leap-second mechanics mentioned. Its closing advice to leave the implementation alone is not adopted as a reason to stop updating dependencies.