title: Convert some local time to UTC in C#
body: <p>I am trying do to something like this:</p>
  
  <p>On a client side I have datepicker for selecting date, drop down for selecting an hour, and drop down with time zones for selecting user time zone.</p>
  
  <p>I am sending this info to server. On a server side, I want to accomplish this:</p>
  
  <p>Take date and time values, and check what is the value of time zone.
  If it is for example "UTC+1" (or any other +- value of UTC time), convert that into UTC, before saving.</p>
  
  <p>What I am not sure how to do it is: What value should I send from client as time zone information so server can detect it is a for example UTC+1.</p>
  
  <p>I saw examples like this:</p>
  
  <pre><code>TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById("Pacific Standard Time"); 
  </code></pre>
  
  <p>On how to find out what is the time zone by its id, but I cannot do something like this:</p>
  
  <pre><code>TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById("UTC+1");  
  </code></pre>
  
  <p>Because, I get an exception, of course:</p>
  
  <blockquote>
    <p>Additional information: The time zone ID 'UTC+1' was not found on the
    local computer.</p>
  </blockquote>
  
  <p>Does someone know what is Id for all UTC+-someNumber, or there is a way to detect timezone from UTC string in some different way?</p>
  
  <p>Did someone had experience whit this kind of a conversion?</p>