diff --git a/README.markdown b/README.markdown
index 6a54a4e9..d32efee3 100644
--- a/README.markdown
+++ b/README.markdown
@@ -508,15 +508,21 @@ ngx.today()
 Returns today's date (in the format `yyyy-mm-dd`) from nginx cached time (no syscall involved unlike Lua's date library).
 .
 
+This is the local time.
+
 ngx.now()
 -------------
 Returns the current timestamp (in the format `yyyy-mm-dd hh:mm:ss`) of the nginx cached time (no syscall involved unlike Lua's date library).
 
+This is the local time.
+
 ngx.time()
 ----------------
 
 Returns the current timestamp (in seconds) of the nginx cached time (no syscall involved unlike Lua's date library).
 
+This is the GMT time.
+
 ngx.cookie_time(sec)
 --------------------
 Returns a formated string can be used as the cookie expiration time. The parameter `sec` is the timestamp in seconds (like those returned from `ngx.time`).