Changing Dates in entire DB

Anybody have a method to change all the Dates in an entire Postgres database?

I have a DB full of data for some demo software. It contains a year's worth of data. I have to manually go thru each year and find every date column and add a year to all dates to keep the demo data current.

Is there an automated way to just check all the tables for any date fields and then add 1 year to every date?

How about an automated way to go thru each table to find the date fields, regardless of table name or field name?