Deceased Father's Missionary Service

We are trying to put together a timeline of my father's WWII military service (he applied for the draft while he was still a missionary in the Southern States Mission) and for this we need definitive dates of his missionary service date/release. Can I obtain this somehow? Thanks.

If his mission call was before 1940, he might appear in this database:
https://history.churchofjesuschrist.org ... e?lang=eng

The database isn't 100% complete, but it's the most complete record that exists up to 1940. Information about the sources of the database can be found here:
https://history.churchofjesuschrist.org ... d?lang=eng