If I correctly understood, you want something like that:
<object id="RefTimeSpan" type="System.TimeSpan">
<constructor-arg name="days" value="6" />
<constructor-arg name="hours" value="0" />
<constructor-arg name="minutes" value="0" />
<constructor-arg name="seconds" value="0" />
</object>
<constructor-arg name="cleanHistoryResourcesAfter" ref="RefTimeSpan" />
<constructor-arg name="cleanResourcesAfter" ref="RefTimeSpan" />