Kieth,
The date 1970-01-01 indicates that the Pi has not set the time on boot. It should get the correct time from the internet when it starts up.
The Python Interval program depends on the time and time zone settings of the Pi for correct operation. Be sure the time zone is set using “sudo raspi-config”, under 4 Internationalisation Options.
You can check the time from the command line with “date”.
There is more information on the wiki at:
http://rayshobby.net/mediawiki/index.php/Real_Time_Clock_%28RTC%29_Set_up
It is not necessary to do a full RTC setup but this should give you some useful information.
Dan