In general, if i were not to brush or floss my teeth for 24 hours can i later brush off tartar accumulation at home that forms? or, too late to?

The rate of: mineralization of dental plaque to calculus or tartar varies from person to person. It is dependent upon saliva chemistry. I cannot recommend going 24 hours as a general practice. You may be able to remove it providing you have excellent oral hygiene skills!!!

Tarter: Soft Dental Plaque (bacteria, food debris) has to be disrupted often (think 2x/day) to prevent the biofilm from doing damage. If calcium from your saliva precipitates out into the plaque it will form Tarter. You cannot effectively remove the Tarter yourself, which is a major reason for having your teeth professionally cleaned 2x/year. If you only brush and don't floss you leave 1/3 of the bugs.