diff --git a/share/zoneinfo/Makefile b/share/zoneinfo/Makefile
index 64d8ee0f1583..0a0b5a5e89b9 100644
--- a/share/zoneinfo/Makefile
+++ b/share/zoneinfo/Makefile
@@ -1,5 +1,31 @@
 # $FreeBSD$
 
+#
+# HOW TO UPDATE THE ZONEINFO DATA
+#
+# In a clean directory, unpack the distribution archive and run:
+#
+# $ cvs -d :ext:ncvs.freebsd.org:/home/ncvs import -b 1.1.2 \
+#	src/share/zoneinfo ADO tzdataYYYYt
+#
+# where YYYYt is the year and the version of the distribution, for
+# example 2004h.
+#
+# Then go to the checked out source, and merge the changes from the
+# previous tag to the new tag in the HEAD:
+#
+# $ cd ../src/share/zoneinfo
+# $ cvs update -jtzdataYYYYp -j tzdataYYYYt
+#
+# Update it again:
+# 
+# $ cvs update
+#
+# And push it back into CVS:
+#
+# $ cvs ci
+#
+
 CLEANFILES+=	yearistype
 
 .if defined(LEAPSECONDS)