diff --git a/libc/Android.mk b/libc/Android.mk
index 97f4011..a6f2c83 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -408,6 +408,14 @@
 		-DUSE_DL_PREFIX \
 		-DPOSIX_MISTAKE
 
+# these macro definitions are required to implement the
+# 'timezone' and 'daylight' global variables, as well as
+# properly update the 'tm_gmtoff' field in 'struct tm'.
+#
+libc_common_cflags += \
+    -DTM_GMTOFF=tm_gmtoff \
+    -DUSG_COMPAT=1
+
 ifeq ($(strip $(DEBUG_BIONIC_LIBC)),true)
   libc_common_cflags += -DDEBUG
 endif
diff --git a/libc/docs/CHANGES.TXT b/libc/docs/CHANGES.TXT
index d7f54ba..c053714 100644
--- a/libc/docs/CHANGES.TXT
+++ b/libc/docs/CHANGES.TXT
@@ -70,6 +70,12 @@
 
 - add sigaltstack() implementation for ARM.
 
+- <time.h>: Properly implement the 'timezone' and 'daylight' global variables
+  (they were not defined previously, though declared in the header).
+
+- <time.h>: Fix timezone management implementation to properly update
+  'tm_gmtoff' field in 'struct tm' structure.
+
 -------------------------------------------------------------------------------
 Differences between Android 2.1 and 2.0.1: