Store Publish dates as date or as string in the Custom metadata

I want to create a custom metadata field Pubdate (Publication date of an eBook or PDF).

This information is normally given as “Month Year” or only “Year” - and that’;s the only granualrity I’m inteersted in either.

Should I store this information better as type string (say “Oct 2015” or “1999”) or as a proper (Applescript) date - and if the latter, how best to fill the unknown info (day & time)?

Any suggestions welcome!

Use a string if you want to control it.