For those who follow Lunar Calendar as per Hindu Vedic system there should be conversion system to convert the English Gregorian Date to Tithi which is Lunar based and as per Hindu Vedic system.
For example the wedding anniversary of someone falling on a particular English date, was on 21st May 2013 which as per Lunar it is a Ekadashi day on which fasting should be observed and if you celebrate as per English calendar it becomes wrong to celebrate this.Similar problems will arise with Lunar dates of Poornima & Amavasya ( Full Moon & New Moon days).
So Geni should give both Solar & Lunar dates!!!
M P Kamath