.TH fmt_iso8601 3 .SH NAME fmt_iso8601 \- write a date in ASCII conforming to ISO-8601 .SH SYNTAX .B #include size_t \fBfmt_iso8601\fP(char *\fIdest\fR,time_t \fIsource\fR); .SH DESCRIPTION fmt_iso8601 writes a date in ASCII representation as ISO-8601 defines it: "2014-05-27T19:22:16Z". ISO-8601 also allows to store a sub-second part and a time zone, but fmt_iso8601 does not support that. fmt_iso8601 does not append \\0. If \fIdest\fR equals FMT_LEN (i.e. is zero), fmt_iso8601 returns the number of bytes it would have written. The return value of fmt_iso8601 is 20 until Jan 1st 10000.