Ability to select Criteria based on todays date - dynamic date

The amount of data being intergrated is relatively large and needs to be filtered. We should be able to export based on a dynamic date setting (under Proposal Selections) so that each day it only exports the latest data and not all the data. We use Task Scheduler to automatically export and need to be able to use "todays" date without any manual entery by the user, each day.