确定夏令时是否处于活动状态？ SQL服务器 [英] Determine if daylight saving time is active? SQL Server

问题描述

我有一个表，其中包含用户，UTC时间偏移量以及他们是否遵守夏时制。有内置的方法来获取正确的用户时间吗？

I have a table with users, UTC time offset, and if they observe daylight saving time. Is there a built in way to get the correct user time?

推荐答案

这并非在所有情况下都有效，但是在美国，将DST定义为3月2日和11月1日之间的快速修复。

This won't work in all cases, but is a quick fix for those in the US w/ DST defined as between the 2nd Sunday of March and the 1st Sunday of November.

DECLARE @Date datetime2 = '2018-11-04 02:01:00'

SELECT 
    CASE 
        WHEN @Date between
            DATETIMEFROMPARTS(YEAR(@Date), 3, (8 - DATEPART(WEEKDAY, DATEFROMPARTS(YEAR(@Date), 3, 1))) + 8, 02, 00, 00, 00)
            and
            DATETIMEFROMPARTS(YEAR(@Date), 11, (8 - DATEPART(WEEKDAY, DATEFROMPARTS(YEAR(@Date), 11, 1))) + 1, 02, 00, 00, 00)
        THEN 1
        ELSE 0
    END --Is it dst?

这篇关于确定夏令时是否处于活动状态？ SQL服务器的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！