Question

I was working with TimeZoneInfo class and ifound some strange stuff, following is my scenario

Time stored in UTC : {3/29/2011 11:30:00 AM}

Now when I started converting it to the user’s respective timezone with the following two methods:

TimeZoneInfo.ConvertTimeFromUtc(date,TimeZoneInfo.ConvertTimeToUtc,{(UTC-05:00) Eastern Time (US & Canada)}
Output: {3/29/2011 6:30:00 AM}

Second way:

  int  offset=
    Convert.ToInt32(,{(UTC-05:00) Eastern Time (US & Canada)}
).BaseUtcOffset.TotalMinutes);

dateTime.AddMinutes(offset);

Output:+    {3/29/2011 7:30:00 AM}

Now as you saw there is difference between these two times, May I know why the difference is coming by doing in either way?

Answer 1

ConvertTimeFromUtc considers any adjustment rules for daylight saving time when converting, whereas BaseUtcOffset returns the timezone’s base offset (without any adjustment rules). If you want the UTC offset for a particular time (including any adjustment rules in effect), use GetUtcOffset.