告诉服务器保存时间的时间，'utc'，然后要求它转换为特定的时区，在这种情况下是'巴西/东部'

quiz_step_progresses.created_at  at time zone 'utc' at time zone 'Brazil/East'

使用以下选择获取时区的完整列表;

select * from pg_timezone_names;

详情请点击这里。

https://popsql.com/learn-sql/postgresql/how-to-convert-utc-to-local-time-zone-in-postgresql

UNIX时间戳只是一个特定日期和UNIX纪元之间的秒数，

SELECT DATEDIFF(SECOND，{d '1970-01-01'}，GETDATE()) //返回SQL server中的UNIX时间戳

你可以创建一个函数，使用Country Offset将本地日期时间转换为Unix UTC SQL server中的Unix时间戳函数

如果你的本地日期时间是东部标准时间，你想从UTC转换为UTC，那么在Azure SQL和SQL Server 2016及以上版本中，你可以这样做:

SELECT YourUtcColumn AT TIME ZONE 'UTC' AT TIME ZONE 'Eastern Standard Time' AS
       LocalTime
FROM   YourTable

时区名称的完整列表可以在以下地址找到:

SELECT * FROM sys.time_zone_info 

是的，时区的命名很糟糕——即使是东部标准时间，也考虑到了夏令时。

这很简单。试试这个Azure SQL Server:

SELECT YourDateTimeColumn AT TIME ZONE 'Eastern Standard Time' FROM YourTable

对于本地SQL Server:

SELECT CONVERT(datetime2, SWITCHOFFSET(CONVERT(datetimeoffset, gETDATE()), DATENAME(TzOffset, gETDATE() AT TIME ZONE 'Eastern Standard Time'))) FROM YourTable

下面的版本考虑了夏令时、UTC抵消，并且没有锁定到特定的年份。

---------------------------------------------------------------------------------------------------
--Name:     udfToLocalTime.sql
--Purpose:  To convert UTC to local US time accounting for DST
--Author:   Patrick Slesicki
--Date:     3/25/2014
--Notes:    Works on SQL Server 2008R2 and later, maybe SQL Server 2008 as well.
--          Good only for US States observing the Energy Policy Act of 2005.
--          Function doesn't apply for years prior to 2007.
--          Function assumes that the 1st day of the week is Sunday.
--Tests:        
--          SELECT dbo.udfToLocalTime('2014-03-09 9:00', DEFAULT)
--          SELECT dbo.udfToLocalTime('2014-03-09 10:00', DEFAULT)
--          SELECT dbo.udfToLocalTime('2014-11-02 8:00', DEFAULT)
--          SELECT dbo.udfToLocalTime('2014-11-02 9:00', DEFAULT)
---------------------------------------------------------------------------------------------------
ALTER FUNCTION udfToLocalTime
    (
    @UtcDateTime    AS DATETIME
    ,@UtcOffset     AS INT = -8 --PST
    )
RETURNS DATETIME
AS 
BEGIN
    DECLARE 
        @PstDateTime    AS DATETIME
        ,@Year          AS CHAR(4)
        ,@DstStart      AS DATETIME
        ,@DstEnd        AS DATETIME
        ,@Mar1          AS DATETIME
        ,@Nov1          AS DATETIME
        ,@MarTime       AS TIME
        ,@NovTime       AS TIME
        ,@Mar1Day       AS INT
        ,@Nov1Day       AS INT
        ,@MarDiff       AS INT
        ,@NovDiff       AS INT

    SELECT
        @Year       = YEAR(@UtcDateTime)
        ,@MarTime   = CONVERT(TIME, DATEADD(HOUR, -@UtcOffset, '1900-01-01 02:00'))
        ,@NovTime   = CONVERT(TIME, DATEADD(HOUR, -@UtcOffset - 1, '1900-01-01 02:00'))
        ,@Mar1      = CONVERT(CHAR(16), @Year + '-03-01 ' + CONVERT(CHAR(5), @MarTime), 126)
        ,@Nov1      = CONVERT(CHAR(16), @Year + '-11-01 ' + CONVERT(CHAR(5), @NovTime), 126)
        ,@Mar1Day   = DATEPART(WEEKDAY, @Mar1)
        ,@Nov1Day   = DATEPART(WEEKDAY, @Nov1)

    --Get number of days between Mar 1 and DST start date
    IF @Mar1Day = 1 SET @MarDiff = 7
    ELSE SET @MarDiff = 15 - @Mar1Day

    --Get number of days between Nov 1 and DST end date
    IF @Nov1Day = 1 SET @NovDiff = 0
    ELSE SET @NovDiff = 8 - @Nov1Day

    --Get DST start and end dates
    SELECT 
        @DstStart   = DATEADD(DAY, @MarDiff, @Mar1)
        ,@DstEnd    = DATEADD(DAY, @NovDiff, @Nov1)

    --Change UTC offset if @UtcDateTime is in DST Range
    IF @UtcDateTime >= @DstStart AND @UtcDateTime < @DstEnd SET @UtcOffset = @UtcOffset + 1

    --Get Conversion
    SET @PstDateTime = DATEADD(HOUR, @UtcOffset, @UtcDateTime)
    RETURN @PstDateTime
END
GO

 declare @mydate2 datetime
 set @mydate2=Getdate()
 select @mydate2 as mydate,
 dateadd(minute, datediff(minute,getdate(),@mydate2),getutcdate())