vendor/tzdata/tzdata2025a

1 files changed, 10 insertions, 0 deletions

diff --git a/factory b/factory
index 9f5fc33023a3..433a672130ee 100644
--- a/factory
+++ b/factory
@@ -8,5 +8,15 @@
 # time zone abbreviation "-00", indicating that the actual time zone
 # is unknown.
 
+# TZ="Factory" was added to TZDB in 1989, and in 2016 its abbreviation
+# was changed to "-00" from a longish English-language error message.
+# Around 2010, CLDR added "Etc/Unknown" for use with TZDB, to stand
+# for an unknown or invalid time zone.  These two notions differ:
+# TZ="Factory" is a valid timezone, so tzalloc("Factory") succeeds, whereas
+# TZ="Etc/Unknown" is invalid and tzalloc("Etc/Unknown") fails.
+# Also, a downstream distributor could modify Factory to be a
+# default timezone suitable for the devices it manufactures,
+# whereas that cannot happen for Etc/Unknown.
+
 # Zone	NAME	STDOFF	RULES	FORMAT
 Zone	Factory	0	-	-00