strftime.3: Move 822-compliant date format example to EXAMPLES section

The RFC 822-compliant date format given in the description
of `%z' is now moved to the `EXAMPLES' section (note: `EXAMPLE'
has been renamed `EXAMPLES').

Furthermore, that format example is now actually
RFC 822-compliant (using `%y' instead of `%Y') and has been
qualified as being correct only when in the context of at least
an English locale. Also, `%T' is used in place of `%H:%M:%S'.

For completeness, an RFC 2822-compliant format example has been
similarly added.

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man3/strftime.3

@@ -250,9 +250,7 @@ The
 .I +hhmm
 or
 .I -hhmm
-numeric timezone (that is, the hour and minute offset from UTC).
-Required to emit RFC\ 822-conformant dates
-(using "%a,\ %d\ %b\ %Y\ %H:%M:%S\ %z"). (SU)
+numeric timezone (that is, the hour and minute offset from UTC). (SU)
 .TP
 .B %Z
 The timezone or name or abbreviation.
@@ -449,7 +447,19 @@ Nowadays,
 .BR gcc (1)
 provides the \fI\-Wno\-format\-y2k\fP option to prevent the warning,
 so that the above workaround is no longer required.
-.SH EXAMPLE
+.SH EXAMPLES
+.BR "RFC\ 2822-compliant date format"
+(with an English locale for %a and %b)
+.PP
+.in +2n
+"%a,\ %d\ %b\ %Y\ %T\ %z"
+.PP
+.BR "RFC\ 822-compliant date format"
+(with an English locale for %a and %b)
+.PP
+.in +2n
+"%a,\ %d\ %b\ %y\ %T\ %z"
+.SS Example Program
 The program below can be used to experiment with
 .BR strftime ().
 .PP
@@ -467,9 +477,10 @@ Result string is "00011"
 Result string is "   11"
 .fi
 .in
-.SS Program source
-\&
+.PP
+Here's the program source:
 .nf
+
 #include <time.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -495,7 +506,7 @@ main(int argc, char *argv[])
 
     printf("Result string is \\"%s\\"\\n", outstr);
     exit(EXIT_SUCCESS);
-} /* main */
+}
 .fi
 .SH "SEE ALSO"
 .BR date (1),