- Time formatting and storage bugs
- The Deep Impact space mission, which tracked time in one-tenth of a second increments, was lost on 11 August 2013 at 00:38:49 when its internal clock reached exactly 232 tenths of a seconds since 1 January 2000, the time value being stored in a signed 32-bit integer which overflowed on the date and at the time in question
- IPv4 address exhaustion, problems caused by the limited allocation size for numeric internet addresses
- ISO 8601, an international standard for representing dates and times, which mandates the use of (at least) four digits for the year
- Perpetual calendar, a calendar valid for many years, including