DateTime2 vs DateTime in SQL Server

Question

Which one:

• datetime
• datetime2

is the recommended way to store date and time in SQL Server 2008+?

I\'m aware of differ

Answer 1

Interpretation of date strings into datetime and datetime2 can be different too, when using non-US DATEFORMAT settings. E.g.

set dateformat dmy
declare @d datetime, @d2 datetime2
select @d = '2013-06-05', @d2 = '2013-06-05'
select @d, @d2

This returns 2013-05-06 (i.e. May 6) for datetime, and 2013-06-05 (i.e. June 5) for datetime2. However, with dateformat set to mdy, both @d and @d2 return 2013-06-05.

The datetime behavior seems at odds with the MSDN documentation of SET DATEFORMAT which states: Some character strings formats, for example ISO 8601, are interpreted independently of the DATEFORMAT setting. Obviously not true!

Until I was bitten by this, I'd always thought that yyyy-mm-dd dates would just be handled right, regardless of the language / locale settings.