diff --git a/modules/acc_radius/doc/acc_radius_admin.xml b/modules/acc_radius/doc/acc_radius_admin.xml
index 17ebd2cce31..f4394579152 100644
--- a/modules/acc_radius/doc/acc_radius_admin.xml
+++ b/modules/acc_radius/doc/acc_radius_admin.xml
@@ -166,6 +166,39 @@ modparam("acc_radius", "radius_extra", "via=$hdr(Via[*]); email=$avp(s:email)")
+
+ rad_time_mode(integer)
+
+ Radius Event-Timestamp for accounting.
+
+
+ Values can be:
+
+
+
+ 0 - (default), format is only unix
+ timestamp for Event-Timestamp (For example: 1445590624)
+
+
+ 1 - format is unix timestamp with microseconds
+ in Addition, it needs to change Event-Timestamp attribute type in dictionary to string
+ both radius server and client
+ (For example: 1445590624.377372)
+
+
+
+
+ Default value is 0 (Unix timestamp).
+
+
+ rad_time_mode example
+
+...
+modparam("acc_radius", "rad_time_mode", 1)
+...
+
+
+