When does the password policy (OU) take effect?

We have defined a OU policy to remove the password expiry (i.e. no more password change is required in the future). However, we foound that this change will not applied to the users immediately. When the user open the “user security” of his ID file, the next password expiry date is still record in the ID file. If the user change the password now, then the expiry date will be removed.

So, it seems that the user has to change the password once in order to remove the password expiry date from the ID file. Is there any way to get rid of it (i.e. the OU policy will be effective immediately after defining it?

Many thanks.