hhmmsssss

HHmmssSSS is a time formatting pattern used in several programming libraries to produce a compact, sortable representation of time. It encodes the hour, minute, second, and millisecond of the day in a 24-hour clock, without separators. Each component is zero-padded: HH ranges from 00 to 23, mm from 00 to 59, ss from 00 to 59, and SSS from 000 to 999.

In libraries that follow this style, such as Java’s date-time formatters, the letters have specific meanings: HH is the hour of the day in 24-hour time, mm the minutes, ss the seconds, and S denotes fractions of a second, with three S characters producing three-digit millisecond precision. The resulting string is a time-only stamp that is easily sortable and can be useful in file names, log suffixes, or compact identifiers.

Example: a time of 14:05:07.123 formatted with HHmmssSSS yields the string 140507123. The pattern reflects the local time of the formatter unless a specific time zone is set (e.g., UTC).

Notes and caveats: because the format omits separators, it is less human-readable and relies on the formatter’s time zone. The S digits are padded to three digits; if higher precision is available, different patterns (such as extending with more S characters) would be needed in libraries that support more digits.

Comparison: other platforms use different tokens for the same idea (for instance, f or fff in some .NET contexts, or %f in Python’s strftime equivalents), so the exact pattern can vary by library.