📋 Time Standards
Understanding the standards that govern time representation in computing.
🌍 UTC (Coordinated Universal Time)
The primary time standard by which the world regulates clocks and time. UTC is the successor to Greenwich Mean Time (GMT) and is not affected by daylight saving time.
Key Points:
- • Always store timestamps in UTC
- • Convert to local time only for display
- • UTC does not observe daylight saving time
- • Leap seconds are occasionally added to UTC
⏰ Unix Time (POSIX Time)
The number of seconds since January 1, 1970, 00:00:00 UTC (the Unix epoch). Widely used in computing systems for timestamp storage.
Current Unix Timestamp:
Important Notes:
- • 32-bit systems will overflow on January 19, 2038 (Y2K38 problem)
- • JavaScript uses milliseconds since epoch, not seconds
- • Does not account for leap seconds
- • Always represents UTC time
🗺️ IANA Time Zone Database
The authoritative source for time zone information, maintained by the Internet Assigned Numbers Authority. Provides historical and current time zone rules for locations worldwide.
Examples:
- • America/New_York
- • Europe/London
- • Asia/Tokyo
- • Australia/Sydney
📅 ISO 8601
International standard for date and time representation. Defines formats for dates, times, durations, and time intervals.
Common Formats:
- • Date: 2024-03-15
- • Time: 14:30:00
- • DateTime: 2024-03-15T14:30:00Z
- • With timezone: 2024-03-15T14:30:00+01:00
📄 RFC 3339
A profile of ISO 8601 for use in Internet protocols. More restrictive than ISO 8601 but widely supported in APIs and web services.
Format:
YYYY-MM-DDTHH:MM:SS[.fraction]±HH:MM
🚧 Coming Soon
- • Windows Time Zone Mappings
- • Leap Seconds and TAI
- • Calendar Systems (Gregorian, Julian, etc.)
- • ISO Week Date System