if 12/7 starts the clock, 10 days of darnkess, then the light would return Dec. 27th. this is an historically important date. after the winter solsitce on the 25th, it isnt untill a couple of days later that the position of the sun has visibly (to the naked eye) started its journey north begining another annual cycle of longer days, easier life, agriculture, etc. this is the basic occult knowlege at the core of late ancient egyt; gnostisism; then modern chrisianity.