When a <Column> under a <FlatFileFormat> has its attribute DataType set to "Date", BIML express emits a DT_DATE column instead of a DT_DBDATE column.

As explained in https://docs.microsoft.com/es-es/sql/integration-services/data-flow/integration-services-data-types?view=sql-server-ver15 :

- DT_DATE : A date structure that consists of year, month, day, hour, minute, seconds, and fractional seconds.
- DT_DBDATE: A date structure that consists of year, month, and day.

According to the previous definition a BIML Date data type should be mapped to a DT_DBDATE.