UTC to locatime with daylight saving

Question

We are saving all dates in UTC in our database and also saving offset for each user.

We are converting to localtime by following function:

 Private Function ConvertToLocalDateTime(ByVal utcOffset As Integer?, ByVal DateToConvert As DateTime?) As DateTime?

        getdatetime = DateToConvert.Value.AddHours(utcOffset)

        If getdatetime.IsDaylightSavingTime Then
            getdatetime.AddHours(-1)
        End If

        Return getdatetime
    End Function

But still dates are 1 or 2 hours off.

How can we convert correctly to localtime from utcoffset also taking care of daylight saving?

See https://learn.microsoft.com/en-us/dotnet/api/system.datetime.tolocaltime?view=netframework-4.8 . *The conversion also takes into account the daylight saving time rule that applies to the time represented by the current DateTime object. * — 3Dave, Sep 11 '19 at 14:32
It's not clear to me why you take a UTC offset as a parameter. Instead, you should take a TimeZoneInfo, as that knows the time zone rules to apply in any situation. If you've only recorded the UTC offset for your users at a particular point in time, you don't have enough information. — Jon Skeet, Sep 11 '19 at 14:32

score 1 · Answer 1 · answered Sep 11 '19 at 14:34

1

As long as the Kind property on DateToConvert is set properly to Utc, then you can just call DateToConvert.ToLocalTime().

answered Sep 11 '19 at 14:34

Gabriel Luci

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UTC to locatime with daylight saving

1 Answers1