How to obtain the timestamp of a schedule for which I get the details?

Please find below the extract from documentation showing the syntax of XML returned by the Web Services call. What is missing for me, is the timestamp. I wonder if you guys encountered this and have any idea how to obtain this (timestamp) information about the schedule via RESTFUL web services ?

<schedule> 
<id>9439</id> 
<name>GC-now-schedule</name> 
<format type="webi"/> 
<status>Completed</status> 
</schedule>