Timestamp

Hi All,

I'm using GNU Radius 1.3.  I would like to use rewrite to set
Event-Timestamp with UTC representation of the current time.

I tried:
%[Event-Timestamp] = time();
Failed: time() isn't supported in rewrite.

I also tried:
%[Event-Timestamp] = %[Timestamp]; where Timestamp is a pseudo attribute.
Failed: can't access Timestamp/Pseudo attribute with %[attrName] it in
rewrite.

I need your advice.  Hope someone could help.  Thanks in advance!!

best wishes,
Wai Chan