Getdate() function to get date for my timezone

问题

I would love to insert a default value into a column with data type datetime2(7). However, because my website is hosted on a server in a different timezone, the getdate function doesn't work properly. I wonder if there is a solution to this. I have done some research and found two ways. First is to use GetUTCDate() function. However, I would need to do the conversion when I display the information. I am sure my web application is used for only my timezone. So I would like to avoid this. Second way, this is the closest I could get this done by using SwitchOffSet function:

CREATE TABLE [dbo].[Test_Date](
[test_id] [int] NOT NULL,
[test_date] [datetime2](7) NOT NULL
) ON [PRIMARY]

GO

ALTER TABLE [dbo].[Test_Date] ADD  CONSTRAINT [DF_Test_Date_test_date]  DEFAULT (switchoffset(CONVERT([datetimeoffset],getutcdate()),'+13:00')) FOR [test_date]
GO

However, my problem is the +13:00 cause in the next few months, it will be +12:00 cause of the day light saving time change. As a result, I would need to change it every time. Anybody has a solution to this?

Thanks.

回答1:

Just store the data in UTC, and use a calendar table to calculate offsets when you read the data (see these tips: part 1, part 2, part 3). Related:

GET UTC Date of a past date

Daylight saving time and time zone best practices

Best Practices working with Datetimeoffset

how to convert all datetime columns in a sql server 2005 express database with data to UTC

Where to set a UTC datetime value in n-tier application: Presentation Layer, Domain, or Database?

How do I handle the timezones for every Chat message

回答2:

You can use SYSDATETIMEOFFSET function

select SYSDATETIMEOFFSET()

MSDN description:

Returns a datetimeoffset(7) value that contains the date and time of the computer on which the instance of SQL Server is running. The time zone offset is included.

回答3:

Since Sql Server 2016 you can use AT TIME ZONE...

SELECT CONVERT(datetime2(0), '2015-03-29T01:01:00', 126)     
AT TIME ZONE 'Central European Standard Time';

... as specified in the documentation

回答4:

SELECT GETDATE() AT TIME ZONE 'UTC' AT TIME ZONE 'Central Standard Time'

You need the first 'AT TIME ZONE UTC' in order to tell the DB what the value currently is in, so it knows how to get to the second given time zone, 'Central Standard Time' in my example.

回答5:

since the db timezone info is different with your web server, its best you explicitly pass your desired datetime value from your web app to the db, instead of using db server-side default function.

来源：https://stackoverflow.com/questions/20086189/getdate-function-to-get-date-for-my-timezone

标签

sql-server

getdate