[3.0] 5449220 Some clarification on how 'now' works I'm not sure if we should go into more detail about how the whole thing works

[Tollef Fog Heen]

commit 5449220e3025a7d62c49b65aa699b55a4f406aac
Author: Per Buer <perbu at varnish-software.com>
Date:   Wed Dec 14 16:04:39 2011 +0100

    Some clarification on how 'now' works
    I'm not sure if we should go into more detail about how the whole thing works

diff --git a/doc/sphinx/reference/vcl.rst b/doc/sphinx/reference/vcl.rst
index 31e51c1..d39128b 100644
--- a/doc/sphinx/reference/vcl.rst
+++ b/doc/sphinx/reference/vcl.rst
@@ -673,7 +673,8 @@ made available to the handler subroutines through global variables.
 The following variables are always available:
 
 now   
-  The current time, in seconds since the epoch.
+  The current time, in seconds since the epoch. When used in string context
+  it returns a formatted string.
 
 The following variables are available in backend declarations: