> Is a "timestamp" field the same as MSSQL server "datetime" field?

Conceptually yes.

Internally they may well be implemented differently, but there is no
need to store the date and time separately. You can always use cast to
convert from a timestamp to date or time.

eg:

select cast(MyTimestampField as Time) as TimeOnly
from ...

select cast(MyTimestampField as Date) as DateOnly
from ...

Adam