I've recently found out about the BUS/252 accrual method used in Brazil, where, to calculate how much of the yearly accrual falls on a given period by calculating the number of business days during that period and then dividing by 252.
Assuming a week has 5 business days we get at least 260, at most 262 business days during a calendar year. What is the reason for 252 being used - is average number of weekday bank holidays in Brazil during calendar year 9? Is there any place online where I can read more on what exactly is considered "business days" for this accrual method?