添加汉斯的评论：

这完全是设计的。时区转换需要具有跟踪世界各地时区规则的数据库的操作系统。在台式机上可用，不受限于像手机这样的设备。没有数据库，您只能知道有关UTC和设备配置的时区。您不能使用PCL，如果这是一个要求，使用商业网络服务为您的转换将成为解决方法。

有看看 Noda时间。这是.NET的日期/时间库，它具有自己的时区数据，因此不必依赖于操作系统。它也支持PCL。

I am developing a project in Xamarin Studio using C#. Its a .net PCL project and my profile is 78. My problem is, i am unable to convert a DateTime from UTC to specified timezone. I am using below code to convert DateTime from UTC to specified local TimeZone.

   DateTime dateTime = (TimeZoneInfo.ConvertTime (DateTime.SpecifyKind (DateTime.UtcNow, DateTimeKind.Utc), profile.TimeZone));

I am getting below exception

The Kind property of the dateTime parameter is DateTimeKind.Utc, but the sourceTimeZone parameter does not equal TimeZoneInfo.Utc.

In PCL TimeZoneInfo.ConvertTime doesn't have a parameter for specifying the TimeZoneInfo sourceTimeZone. It has only 2 overloads with below parameters.

ConvertTime(DateTime, TimeZoneInfo) & ConvertTime(DateTimeOffset, TimeZoneInfo)

TimeZoneInfo exist only to specify destination TimeZoneInfo.

Also it doesn't have TimeZoneInfo.ConvertTimeFromUtc, TimeZoneInfo.ConvertTimeToUtc Methods.

Please someone help me to fix this.

To add to Hans's comment:

This is all entirely by design. Timezone conversions requires an operating system with a database that keeps track of the timezone rules across the world. Available on a desktop class machine, not available on limited devices like a phone. Without the database, you can only know something about UTC and the timezone for which the device was configured. You cannot use PCL if this is a requirement, using a commercial web service to make the conversion for you would be a workaround.

Have a look at Noda Time. This is a Date/Time library for .NET which has its own time zone data so it doesn't have to rely on the OS. It also supports PCLs.