1--- a/src/time/__tz.c
2+++ b/src/time/__tz.c
3@@ -23,6 +23,9 @@ static int r0[5], r1[5];
4 static const unsigned char *zi, *trans, *index, *types, *abbrevs, *abbrevs_end;
5 static size_t map_size;
6 
7+static const char *tzfile;
8+static size_t tzfile_size;
9+
10 static char old_tz_buf[32];
11 static char *old_tz = old_tz_buf;
12 static size_t old_tz_size = sizeof old_tz_buf;
13@@ -125,6 +128,15 @@ static void do_tzset()
14 		"/usr/share/zoneinfo/\0/share/zoneinfo/\0/etc/zoneinfo/\0";
15 
16 	s = getenv("TZ");
17+
18+	/* if TZ is empty try to read it from /etc/TZ */
19+	if (!s || !*s) {
20+		if (tzfile)
21+			__munmap((void*)tzfile, tzfile_size);
22+
23+		s = tzfile = (void *)__map_file("/etc/TZ", &tzfile_size);
24+	}
25+
26 	if (!s) s = "/etc/localtime";
27 	if (!*s) s = __gmt;
28 
29