diff --git a/wiki/macro/BirthDate.py b/wiki/macro/BirthDate.py
new file mode 100644
index 00000000..dd2ab96b
--- /dev/null
+++ b/wiki/macro/BirthDate.py
@@ -0,0 +1,18 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from MoinMoin.wikiutil import escape
+
+import time
+import datetime
+import re
+
+def execute(macro, text):
+    year, month, day = text.split(",")
+    y, m, d = int(year), int(month), int(day)
+    now = datetime.datetime(*time.localtime()[:6])
+    birthdate = datetime.datetime(now.year, m, d)
+    age = now.year - y
+    if now < birthdate:
+        age -= 1
+    return macro.formatter.text(str(age))