title: how to get UTC time of a past date using asp.net and c# or sql server
body: <p>Can you guide me to get utc time of a given date (which can be either in the past,current time). Let us say user enters the date in the format of 12-AUG-2013 17:10 PHT. Is it possible to get the UTC time of that given date? I am using asp.net and c# 3.5 and sql server 2008 for my project. Please suggest me ways to implement this option. Please let us know for more information regarding my query. Thanks</p>
  
  <p>PHT is not part of the input string, but i append it to display that its Phillines time zone. But i get this abbrevations from admin screen where the country,timedifference to UTC/GMT and abbrevations of time zone are stored.</p>
  
  <p>I would give the details of my requirement. User enters a date of his/her local time zone. This date can be the date in past or current one. For example, user is entering the date 12-AUG-2013 17:10  which is a phillipines date and time (Let us say). I want this date to be converted to UTC/GMT date and time. How i do it is, I ask admin user to store time difference for each country. when the user enters the date and based on the selected country, i decide it as phillipnes date and time if the user has selected country Phillipines.Then i add or substract that timedifference to get the UTC/GMT date. My concern is if user enters the date and time of a past time, then how can we get the UTC time of that date because we can only get the current UTC time. Hope I could give you enough details. I know the code and able to google and all but i need good approach to do this. I just need concept to do it.</p>