How to convert a date to UTC properly and then convert it back?

Question

I\'m struggling with converting DateTime to UTC, the concept and all, something I\'m not understanding correctly.

When I get a date time string, say \"7/10/2013\", I si

Answer 1

I have had the same issue and i made the following extension methods.

    public const string UTC = "UTC";

   public static DateTime Convert(this DateTime date, string fromZone, string toZone)
    {
        TimeZoneInfo to = TimeZoneInfo.FindSystemTimeZoneById(toZone);
        TimeZoneInfo from = TimeZoneInfo.FindSystemTimeZoneById(fromZone);
        return new DateTime(TimeZoneInfo.ConvertTime(date, from, to).Ticks, DateTimeKind.Unspecified); 
    }

    public static bool IsDayLightSaving(this DateTime date, string zone)
    {
        TimeZoneInfo to = TimeZoneInfo.FindSystemTimeZoneById(zone);
        return to.IsDaylightSavingTime(date);
    }

    public static DateTime ConvertToUTC(this DateTime date, string fromZone)
    {
        return date.Convert(fromZone, DateTime_Extension.UTC);
    }

    public static DateTime ConvertToLocal(this DateTime date, string toZone)
    {
        return date.Convert(DateTime_Extension.UTC, toZone);
    }

The problem I found is actually finding the current users Time Zone. As this is not passed in the Header (you can get it via JavaScript) I have decided to ask the user to select their time zones when they register

Hope this helps