size_t strftime

size_t strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr)

A complete description of strftime() is beyond the pale of this document. Refer to ISO/IEC document 9899 for details.

All conversions are made using the 'C Locale', ignoring the E or O modifiers. Due to the lack of a time zone 'name', the 'Z' conversion is also ignored.