SSIS - OLEDate CAST vs Implicit conversion to DT_DBDATE vs DateTime.FromOADate()
About date serials (OLE Dates) Date Serial represents the number of Days between the date value and the initial value that is 1899-12-30 Date Serials are used in Microsoft Excel and many other platform. You can Read more about Date Serials at: Why is 1899-12-30 the zero date in Access / SQL Server instead of 12/31? T-SQL to convert Excel Date Serial Number to Regular Date Date Serials in SSIS We can convert date serials to datetime using CAST method in the OLEDB Source SQL Command , or converting it using a script component DateTime.FromOADate() method, or we can connecting it directly to a DBTYPE_DATE column. but there is difference between these methods 1) CAST method From Microsoft Docs - CAST and CONVERT (Transact-SQL) : " Only supported when casting from character data to datetime or smalldatetime. When character data that represents only date or only time components is cast to the datetime or smalldatetime data types, the unspecified time compon