The Importacular mapping area of Volunteer Availability is linked to the Availability/Interests section on the Volunteer tab of the Constituent’s record.
The Volunteer Availability section allows you to track when your volunteers would like to serve. It functions with generalities and not specific dates. As seen below, you would choose just the month and the day rather than a full date including the year for the From Date and To Date.
Please note that the From Date and To Date are required and they are also key fields (meaning that, if for any reason, they are unpopulated, the Availability mapping will not populate).
Please note the area settings for Volunteer Availability:
These allow you to select which fields constitute a match to the data already in RE and what you would like to do with that data (add anyway, update RE or leave RE as is).