我正在构建一个应用程序，需要计算“两个日期之间有多少个星期/几个月/几年”以及我所有用户来自单个时区的内容。
我想知道，为此更好地使用SELECT
DcProd.Title,
EfProd.Name,
DcProd.Summary,
DcProd.Product,
EfProd.ProductStatus,
EfProd.ViewOnlyLicenses,
EfProd.FullLicenses,
DcProd.Advertise,
EfProd.CustomerAccount_Id,
DcPageRelation.url_name_,
CASE
WHEN DcProd.ProductType = 1 THEN 'Module'
WHEN DcProd.ProductType = 2 THEN 'Portal Add-On'
WHEN DcProd.ProductType = 3 THEN 'Language'
WHEN DcProd.ProductType = 4 THEN 'Jumpstart'
WHEN DcProd.ProductType = 5 THEN 'Documents Connector'
WHEN DcProd.ProductType = 6 THEN 'Documents Add-On'
WHEN DcProd.ProductType = 7 THEN 'Express'
WHEN DcProd.ProductType = 8 THEN 'Process Add-On'
WHEN DcProd.ProductType = 9 THEN 'Process Solution'
WHEN DcProd.ProductType = 10 THEN 'Training Add-On'
ELSE null END AS ProdType,
(SELECT DcRelation2.child_item_additional_info
FROM [MC_Sitefinity].[dbo].[sf_dynamic_content] AS DcStatus2
LEFT JOIN
[MC_Sitefinity].[dbo].[sf_content_link] AS DcRelation2 ON DcStatus2.original_content_id = DcRelation2.parent_item_id AND DcRelation2.component_property_name='Image'
WHERE DcProd.base_id= DcStatus2.base_id) as theimage
FROM
[MC_Sitefinity].[dbo].[mastercontrolproducts_mastercontrolproduct] AS DcProd
LEFT JOIN
[MasterControlSitefinity].[dbo].[ProductLicense] AS EfProd ON DcProd.Product = EfProd.Product_Id
AND EfProd.CustomerAccount_Id = @CustomerId --matching dynamic content (Dc) products to Entity Framework (Ef) products
LEFT JOIN
[MC_Sitefinity].[dbo].[sf_dynamic_content] AS DcStatus ON DcProd.base_id = DcStatus.base_id -- show only published and visible.
LEFT JOIN
[MC_Sitefinity].[dbo].[sf_content_link] AS DcRelation ON DcStatus.original_content_id = DcRelation.parent_item_id
AND DcRelation.component_property_name = 'ProductPageUrl' --Gets related items for page url
LEFT JOIN
[MC_Sitefinity].[dbo].[sf_page_node] AS DcPageRelation ON DcRelation.child_item_id = DcPageRelation.id --gets page url for query
WHERE
DcStatus.visible = 1
AND DcStatus.approval_workflow_state_ = 'Published'
ORDER BY
ProdType
（因为我只使用一个时区）或LocalDateTime（考虑可能的DST和偏移量变化）？
另外，我在做
时是对的ZonedDateTime答案 0 :(得分：3)
对于第一种方案，请使用LocalDate类型以及Period.Between方法。
对于第二种情况，你可以构建一个类似的LocalDateTime，但结果值将反映“UTC日” - 这是一个人工构造。
每当你需要“现在”时：
IClock实施开始，例如SystemClock.Instance。Instant获取.Now。.InZone即时投影到该区域中的ZonedDateTime。.Date以获取LocalDate个实例，以便与您询问的第一个方案一起使用。一般情况下，尽量避免调用DateTime.Now或DateTime.UtcNow。当然，有些地方你可以用它来进行短切，但API不一定会引导你得出正确的结论。
总结两种情况：
// assuming you start with a DateTime, perhaps from a db.
DateTime dt = new DateTime(2016,1,1);
LocalDate ldt = LocalDateTime.FromDateTime(dt).Date;
DateTimeZone tz = DateTimeZoneProviders.Tzdb["America/New_York"];
ZonedDateTime now = SystemClock.Instance.Now.InZone(tz);
LocalDate today = now.Date;
Period period = Period.Between(today, ldt, PeriodUnits.YearMonthDay);
int years = (int) period.Years;
int months = (int) period.Months;
int days = (int) period.Days;
另外，请注意在Noda Time 2.0（目前处于alpha版本）中，它有点简单：
DateTime dt = new DateTime(2016, 1, 1);
LocalDate ldt = LocalDate.FromDateTime(dt); // 2.0
DateTimeZone tz = DateTimeZoneProviders.Tzdb["America/New_York"];
LocalDate today = SystemClock.Instance.InZone(tz).GetCurrentDate(); // 2.0
Period period = Period.Between(today, ldt, PeriodUnits.YearMonthDay);
int years = (int)period.Years;
int months = (int)period.Months;
int days = (int)period.Days;