Robert - this is clearly not normal behavior. Normally, you would synchronize the database once, there would be no errors, and you would not have to synchronize again until you made further modeler changes that affect the database structure.
I'm sure I've seen this or a very similar issue a long time ago at a potential client site, but I can't remember the details. It was caused by a configuration they had set in MS SQL Server which stopped Mendix making changes it wished to for timezone calculations. The fix from Mendix was a special Runtime configuration setting to change the behavior of Mendix and avoid the error message... but I can't find what that setting was....
I've just searched my email history and the forum and found this: What-Database-Permissions-are-needed-to-run-Mendix. I'm not sure it's the same issue, but it sounds similar. HTH