“In order to accommodate the forthcoming Conclave, the Sistine Chapel will remain closed to the public from 1 pm on Tuesday 5 March until further notice. During the same period, the Borgia Apartment and the Collection of Modern Religious Art will not be included in visits to the Vatican Museums.”.(From Vatican Website)
The Chapel was closed just before the lunch hour. Since it took about 7 days to prepare the Chapel for the Conclave last time,, The earliest possible date would be March 12th, if past experience is any indicator of how long it will take to prepare this time. Why so long? A false floor is placed on top of the floor to some how or other make the Chapel secure and free from electronic bugging devices etc..At the morning meeting of Cardinals there were still 5 missing. A date can not be set unless all are present.