I'm trying to display datetime values in local time. By default, Azure SQL Database stores dates and times in UTC, there is no way around this. (This was a pain when migrating from on premise SQL Server.) I would like to display a stored time value in Central European time.
Now the local time is 11:30 (CET). UTC time is 10:30.
DECLARE #TestTime DATETIME;
SET #TestTime = '2016-11-02 10:30:00'
SELECT #TestTime
--Returns 2016-11-02 10:30:00
SELECT #TestTime AT TIME ZONE 'Central European Standard Time'
--Returns 02 November 2016 10:30:00 +01:00
I need to return 2016-11-02 11:30:00 somehow. Now for the fun part:
As has been suggested here:
SELECT convert(DATETIME,#TestTime AT TIME ZONE 'Central European Standard Time',1)
--Returns 2016-11-02 09:30:00 So instead of adding the timezonedifference it subtracts it.
This works, but makes me sick:
SELECT DATEADD(MINUTE,DATEPART(tz,#TestTime AT TIME ZONE 'Central European Standard Time'),#TestTime)
--Returns 2016-11-02 11:30:00
A similar solution has been suggested here, but it plays with string operations. My suspicion is that something is wrong in AT TIME ZONE; it should have displayed 11:30 +1, and not 10:30 +1, no?
Is there really no proper way to display a UTC time in local time? This "hacking around it" feels awfully dirty, especially since at any point in time it just might stop working (e.g. Microsoft fixes / introduces a bug).
Thanks!
The AT TIME ZONE statement performs two distinct operations:
To assert that a datetime (or datetime2) is in a particular time zone, thus looking up the correct offset for that zone and returning a datetimeoffset value with the correct offset applied.
To convert a datetimeoffset value to a different time zone, using the offset from the source value to pin down an exact point in time, then looking up the new offset for the requested time zone and applying it. This returns a datetimeoffset with a potentially different local time and offset than the original, but representing the same moment in time.
You are using the first part only. To convert a datetime from UTC to a specific time zone, you'll need to use both.
SELECT #TestTime AT TIME ZONE 'UTC' AT TIME ZONE 'Central European Standard Time'
The first AT TIME ZONE asserts that the input datetime is in UTC, resulting in a datetimeoffset that has +00:00 for the offset. The second AT TIME ZONE converts that to the time zone requested.
Related
I have a database that records time in UTC. I need to convert this time to Local Time, and then aggregate the data by Month on this new Local Time that I have created. Everything works fine if I just aggregate on the original UTC Time, but of course, the value that I get at the end is slightly off which does not work for me. However, if I try to aggregate on Local Time, I just can't get it to work.
I am unable to use TIMESTAMP_LOCAL in my GROUP BY Clause, and neither am I able to use the whole YEAR(CONVERT(DATETIME2(3), TIMESTAMP_UTC AT TIME ZONE 'UTC' AT TIME ZONE 'Central European Standard Time'). Same goes for the entire DATEFROMPARTS Function.
SELECT
SUM([VALUE]) AS Required_Value
,DATEFROMPARTS(YEAR(CONVERT(DATETIME2(3), TIMESTAMP_UTC AT TIME ZONE 'UTC' AT TIME ZONE 'Central European Standard Time')), MONTH(CONVERT(DATETIME2(3), TIMESTAMP_UTC AT TIME ZONE 'UTC' AT TIME ZONE 'Central European Standard Time')), 1) AS TIMESTAMP_LOCAL
FROM [DB].[TABLE]
GROUP BY ???
I have a table that stores the transaction date time in UTC time zone. I would need to convert this time to eastern time zone i.e. EST or EDT, depending on the transaction date.
How can I do this without writing a big function or creating a table / view that flags EST / EDT for each transaction date?
Use AT TIME ZONE, which changes the timezone of a value to the relevant time there, and observes Daylight Saving:
SELECT CONVERT(datetimeoffset(0),'2021-09-07T15:25:37+00:00') AT TIME ZONE 'Eastern Standard Time' AS Sep21,
CONVERT(datetimeoffset(0),'2021-01-09T15:25:37+00:00') AT TIME ZONE 'Eastern Standard Time' AS Jan21;
Which returns the following:
Sep21 Jan21
---------------------------------- ----------------------------------
2021-09-07 11:25:37 -04:00 2021-01-09 10:25:37 -05:00
The below SQL will convert the UTC time to my local time in BRISBANE, Australia.
I would like to get the Local time in Sydney which is 1 hour ahead of Brisbane time considering the DST
SELECT
GETUTCDATE() AS UTCTime,
CAST(GETUTCDATE() AT TIME ZONE 'UTC' AT TIME ZONE 'E. Australia Standard Time' AS DATETIME2(2)) AS BrisbaneTime
Need some assistance in getting the local time in Sydney.
All of the possible timezones are defined in the sys.time_zone_info system table. From there you can select the appropriate timeone to use.
You would use the same query but with the other timezone
I am using SQL Server 2014
Currently, I am using MSSQL function:
format(TODATETIMEOFFSET(("[dateColumn]",'-6:00'),'MM/dd/yyyy')
However, this will not apply Daylight savings.
How can i achieve it?
Please help
This answer was provided before information was received that the OP was using SQL Server 2014 (which I have now added to their tags). I have left the answer here, however, as it will likely be helpful for future readers using a more recent version of SQL Server.
UTC -6 will always be UTC -6; it doesn't change for daylight savings and become UTC -5. Timezones like GMT (UTC+0) and EST (UTC-5) change to BST and EDT but then they also respectively become UTC +1 AND UTC -4. You're providing a literal number so the value will always be UTC -6.
What you are likely looking for is AT TIME ZONE (AT TIME ZONE (Transact-SQL), which was introduced with SQL Server 2016. For example:
--Returns 2018-01-01 18:00:00 -06:00
SELECT CONVERT(datetime2(0), '2018-01-01T18:00:00') AT TIME ZONE 'Central Standard Time';
--Returns 2018-07-01 18:00:00 -05:00 (changes to -5, due to daylight saving)
SELECT CONVERT(datetime2(0), '2018-07-01T18:00:00') AT TIME ZONE 'Central Standard Time';
I am trying to use the new AT TIME ZONE syntax in SQL Server 2016 and Azure SQL. I'm just trying to get the current time in London as a datetime, adjusted for daylight saving. At the time of running all of the commands below, the time in London was 3.27am.
The first step is to get a datetimeoffset, which I can successfully do as follows:
DECLARE #dto datetimeoffset
SET #dto = (SELECT GETUTCDATE() AT TIME ZONE 'GMT Standard Time')
SELECT #dto
This returns a value as I would expect:
2016-04-04 02:27:54.0200000 +01:00
Next, I want to convert that to a datetime, which is what my applications expect. I've tried three different approaches, none of which give me the result I'm looking for:
SELECT SWITCHOFFSET(#dto,'+00:00')
-- Returns 2016-04-04 01:27:54.0200000 +00:00
SELECT CONVERT(datetime, #dto)
-- Returns 2016-04-04 02:27:54.020
SELECT CONVERT(datetime2, #dto)
-- Returns 2016-04-04 02:27:54.0200000
I feel like I'm missing something obvious - is there an easy way to take a datetimeoffset and return just the date/time part at that offset?
The first line of your code contains the fault:
SELECT GETUTCDATE() AT TIME ZONE 'GMT Standard Time'
GETUTCDATE() returns a datetime, which has no time zone offset information. Thus as described in the MSDN documentation:
If inputdate is provided without offset information, the function applies the offset of the time zone assuming that inputdate value is provided in the target time zone.
So, even though you retrieved the UTC time, you erroneously asserted that the value was in London time (which is UTC+1 for daylight saving time at this date).
The easiest way to handle this is to just fetch the UTC time as a datetimeoffset to begin with.
SELECT SYSDATETIMEOFFSET() AT TIME ZONE 'GMT Standard Time'
This invokes the conversion functionality of AT TIME ZONE, which in the docs states:
If inputdate is provided as a datetimeoffset value, then AT TIME ZONE clause converts it into the target time zone using time zone conversion rules.
Consider that if your data actually comes from a datetime field somewhere, you might need to use both parts of the functionality, like this:
SELECT mydatetimefield AT TIME ZONE 'UTC' AT TIME ZONE 'GMT Standard Time'
The first call to AT TIME ZONE asserts the value is in UTC, giving a datetimeoffset to the second call, which converts it to London time.
The output of any of these is a datetimeoffset, which you can cast or convert to a datetime or datetime2 exactly as you showed in your original question. (Don't use switchoffset for this.)
Also, the Windows time zone identifier for London is always "GMT Standard Time". It is inclusive of both Greenwich Mean Time and British Summer Time, with the appropriate transitions between them. Do not try change it to "GMT Daylight Time" - that identifier doesn't exist. This is also covered in the timezone tag wiki, in the section on Windows time zones.
Since I was unable to find this anywhere else I thought I'd share. You can get the offset in minutes by using datepart (tz) with AT TIME ZONE.
datepart(tz,UTC_Date AT TIME ZONE 'Central Standard Time')
select dateadd(MINUTE,datepart(tz,cast('2018-07-02 17:54:41.537' as datetime) AT Time Zone 'Central Standard Time'),'2018-07-02 17:54:41.537') as CentralTime
returns
CentralTime
2018-07-02 12:54:41.537
I suggest you only store this as a string and qualify that it is a local time representation, otherwise the time SQL Server stores internally would be the wrong actual/physical time, if the server time is correct, but just not in the same time zone. It is why you cannot use convert to represent the same because you are actually changing the datetime value from the real time of occurrence and not just re-representing it i.e. Datetime is always stored as UTC, but entered and displayed in the timezone of the server, so if you enter a local time in a datetime field, the server interprets that time as the time in the server time zone and not the actual time of the event, which results in stored time navigation/deviation if the local time is not the same as the server> Should you then feed the same data to other systems in different time zones, they will have incorrect data and it can get messy. Store the right value in the datetime field and display it as you wish as a string.