从JavaScript客户端发送到.NET的字符串格式的UTC日期已转换为DateTime

Question

I am working with a client application written in JavaScript which sends data to ASP.NET web api end point (server).

I am asking user to select a date & time. I convert the that date into UTC datetime as string using . toUTCString().

I send this information to .NET application, which expects the value to be of DateTime type.

The value I am sending = Thu, 31 Dec 2015 03:30:00 GMT

value I receive on .net side = {12/30/2015 10:30:00 PM}

I understand the value is getting converted. My question is: How can I convert the date to UTC on the server side. My assumption is there is no implicit timezone offset attached to a DateTime object. If I run ToUniversalTime() on it when I'm running the code in Greenwich, then I get the same time. If I do it while I live in Vancouver, then I get an offset DateTime object of -8 hours.

So I a client coming from different location and I convert that time into UTC by using .ToUniversalTime() , the conversion will be wrong. How do I overcome this problem?

Answer 1

If a user selects date and time I assume it's not current and is relative to the user. In this case yes, you would want to convert to UTC if you want to further analyze data or present it to another user in another timezone. If you don't convert it to UTC, you would receive relative date/time and would need another data that indicates timezone. But even in that case, there is no point other than security measures to compute on the server something that could be easily computed on the client.