SQL Server How to persist and use a time across different time zones

Question

In SQL Server I would like to create a table to save time of an event, and would like to convert it into the timezone of the users choice for display purposes. Let us say th

Answer 1

In SQL Server 2008, use the DATETIMEOFFSET data type which is a DATETIME plus a timezone offset included.

SELECT CAST('2010-11-23 16:35:29+09:00' AS datetimeoffset) 

would be Nov 23, 2010, 4:35pm in a +9 hour (from GMT) timezone.

SQL Server 2008 also contains functions and SQL commands to convert DATETIMEOFFSET values from one timezone to another:

SELECT 
SWITCHOFFSET(CAST('2010-11-23 16:35:29+09:00' AS datetimeoffset), '+01:00')

would result in:

2010-11-23 08:35:29.0000000 +01:00

Same time, different timezone (+1 hour from GMT)