YYYYMMDDTHHMMSSmmmZ

The ISO 8601 standard defines a universal format for representing dates and times in a machine-readable and human-interpretable manner. One such format within this standard is "YYYYMMDDTHHMMSSmmmZ," which combines a date and time with millisecond precision and a timezone indicator.

In this format, "YYYY" represents the four-digit year (e.g., 2023), followed by "MM" for the two-digit month (01 for January through 12 for December), and "DD" for the two-digit day of the month (01–31). The "T" character separates the date from the time component. The time is broken down into "HH" for hours (00–23), "MM" for minutes (00–59), and "SS" for seconds (00–59). The "mmm" suffix denotes milliseconds (000–999), providing sub-second granularity. Finally, "Z" indicates Coordinated Universal Time (UTC), ensuring global consistency without daylight saving time adjustments.

This format is widely used in digital systems, including APIs, databases, and logging applications, due to its unambiguous structure. For example, "20230515T143022123Z" represents May 15, 2023, at 14:30:22.123 UTC. Variations may omit the "Z" to include an offset (e.g., "+05:30") or replace "Z" with a timezone abbreviation, though the latter is less standardized.

The format’s simplicity and precision make it ideal for timestamping events, synchronizing systems, and ensuring compatibility across platforms. It is particularly useful in scenarios requiring strict temporal ordering or compliance with international standards.