NBRBRates add-on provides new custom function to your spreadsheet. The function is called NBRBRate. It returns National Bank of Belarus currency exchange rate for Belarusian Ruble to other given currency on given date. Depending on the date local currency is BYN (starting 7/1/2016), BYR (1/1/2000 – 6/30/2016) or BYB (prior to 1/1/2000). To use it just put into your formula the function call: NBRBRate(currency), for example NBRBRate("USD"). Use the second argument when you want to provide the date: NBRBRate(currency, date), like NBRBRate("USD", TODAY()+1).