Duration for a new zoneinfo file

Hello, At the moment we have the situation that in the country of some customers the head of these countries decides to change the time/date for changing of winter/summertime. Now I would like to know how long it would approximately need until a new zoneinfo file is created after you received a message that there will be a change? This is important for us, because SUN is using your zoneinfo files as input for JAVA which we are using. Thanks for your help. Kind Regards, Matthias Rest