There is only up 6th on the drop-down list as it is describing the nth week not the particular day of the month.
To configure the time, log in to the web interface of the ENS202EXT and click on Time Settings
Check the box beside Enable Daylight Saving.
Set the Start to March/2nd/Sunday/ and offset to 2am (March 8, 2015 02:00) and set the end to November/1st/Sunday/2am (November 1, 2015 02:00)
Click Save/Apply to save the settings.