The amount of outstanding principal shall bear interest at a rate of ten percent (10%) per annum from March 4, 2015 ; provided, however, upon the occurrence of an uncured Event of Default, the outstanding principal at the time of such uncured Event of Default shall accrue at the rate of seventeen percent (17%) per annum during the period of time which the Event of Default is continuing and not cured, and the amount of any and all such default interest shall be payable on demand by the Holder.  Interest shall accrue on the princi-pal balance from March 4, 2015 and shall be calculated on the basis of a 365-day year.