Except they gave people 3 days to exchange any that they had, and it was announced at 9pm on the day immediately preceding that 3-day period.
The end result is that they effectively took out 14 billion rubles from circulation - i.e. country residents were collectively robbed of that amount of money.
A similar thing was repeated in 1993, except with a 2 week timeframe to exchange.
When such procedure is done properly for legitimate reasons, the timeframe is usually set to several years.