SQL & PL/SQL

In my application I have two configurable settings that only a user with necessary priviledges can set ...

1) EARLIEST_DATE_ALLOWED and
2) LATEST_YEAR_ALLOWED.

Through the front end validation works fine as when a user tries to enter dates outside this range an error message is dislpayed.

However,

The validation does not work when inserting data through api's (e.g. large records of data as a batch). The system allows dates outside these ranges to be inserted, even when the above 2 settings have been configured not to allow this.

My approach is to add a validating function to a library package I have and then make calls to this package from the 10 or so api's I have.....thus when a user tries to insert a date that is outside this range, an error is given.

Any ideas on how to structure or develop this function....I want to keep it as simple as possible....

Thanks folks!