From my brief research, it seems a lot of important dates have no Day and Month, just the Year. I guess the days and months were not so important to the ancients? Birth records were not accurate with the ancients.? Perhaps the calender can be modified to reflect this, i dont know how exactly, ill leave that to you :P Instead of a Yearly Calender, maybe a Millenium Calender that starts from the The Hijra in Medina until the year 20xx? (that gives us 1400 plus references) It kind of defeats the purpose of your task, so ignore the suggestion if im just being lazy with the research What do you think brother?