Substitute the render time in the file name

Hello.
I would like to render in the file name will be substituted into the render time. That is, with long-term beneficial to specify in the name of something like "myrenderfilename-<%rendertime%>", go to sleep, and woke up to find the render named "myrenderfilename-5h48m37s". Is it possible?
Comments
You can get the render time from the log - View>Troubleshooting>View Log. If you left DS rendering then when you open the log it should be the last line, or very nearly.
Thanks Richard
It is not exactly what I wanted to, but for lack of a better ... )