diff --git a/book/index.adoc b/book/index.adoc
index b673ffb..51717b8 100644
--- a/book/index.adoc
+++ b/book/index.adoc
@@ -12,7 +12,7 @@
 :leveloffset: +1
 :pygments-linenums-mode: table
 :pygments-style: vs
-:revdate: {date}
+:revdate: {docdatetime}
 :revnumber: v0.0.1
 :revremark: Under development
 :sectlinks: