Tank you!
I follow your example. It didnt work at first. I found out that I had to add time library first.
<?xml version="1.0" encoding="utf-16"?>
<!--VoxCommando 2.1.4.6-->
<command id="667" name="convert time stamp" enabled="true" alwaysOn="False" confirm="False" requiredConfidence="0" loop="False" loopDelay="0" loopMax="0" description="">
<action>
<cmdType>PY.ExecString</cmdType>
<params>
<param>import time; result= time.ctime(1430337630)</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<action>
<cmdType>OSD.ShowText</cmdType>
<params>
<param>The time is {LastResult}</param>
</params>
<cmdRepeat>1</cmdRepeat>
</action>
<phrase>convert time stamp</phrase>
</command>