In sandyf 

Deleting zeros from the currency is the process of replacing the old currency with a new one whose price is less than the old currency by the number of zeros that will be deleted, for example deleting three zeros from the Iraqi currency means that one dinar from the new currency is equivalent to 1000 dinars from the old currency. – A Redenomination. The term “strengthen the national currency” is regularly used by central banks and usually means they have to try and stop the currency from further weakening.  A redenomination means a change in the monetary unit and any such changes must be approved by parliament. Normal timeframe is around 2 years.