Elemental mercury is a shiny, silver-white metal that is a liquid at room temperature and is traditionally used in thermometers and some electrical switches. If not enclosed, at room temperature some of the metallic mercury will evaporate and form mercury vapours. Mercury vapours are colourless and odourless.
How much time need to pass for an AR account to be considered delinquent? The amount of time required to pass for an AR account to be  considered delinquent is 30 days.
That is traditionally the point at which companies write off their debt--where they realize that the delinquent account may not be collectable. Within the 30-180 day period, companies will try various tactics to collect the money, using their internal people: bookkeepers, comptrollers, or even their corporate attorney.