+The system timezone file.
+.TP
+.I /usr/share/zoneinfo/
+The system timezone database directory.
+.TP
+.I /usr/share/zoneinfo/posixrules
+When a TZ string includes a dst timezone without anything following it,
+then this file is used for the start/end rules.
+It is in the
+.BR tzfile (5)
+format.
+By default, the zoneinfo Makefile hard links it to the
+.IR America/New_York " tzfile."
+.PP
+Above are the current standard file locations, but they are
+configurable when glibc is compiled.
+.SH ATTRIBUTES
+For an explanation of the terms used in this section, see
+.BR attributes (7).
+.TS
+allbox;
+lb lb lb
+l l l.
+Interface Attribute Value
+T{
+.BR tzset ()
+T} Thread safety MT-Safe env locale
+.TE