C#•2y ago

❔ DateTime help with NodaTime

So I receive timeseries data from an API which I then save in a db. The API delivers the data in hourly timespans, which are always using the Central European Standard Time zone. I want to save it in UTC format in the database, but daylight savings is giving me a real headache.. Take October 30th 2022, the data looks like this:

"Date": "2022-10-30T00:00:00",
      "Base": 1173.386,
      "TimeSpans": [
        {
          "TimeSpan": "00:00-01:00",
          "Value": 1030.94
        },
        {
          "TimeSpan": "01:00-02:00",
          "Value": 1009.4
        },
        {
          "TimeSpan": "02:00-02:00",
          "Value": 1006.71
        },
        {
          "TimeSpan": "dst",
          "Value": 1003.41
        },
        {
          "TimeSpan": "03:00-04:00",
          "Value": 984.24
        },
        {
          "TimeSpan": "04:00-05:00",
          "Value": 985.68
        },
        {
          "TimeSpan": "05:00-06:00",
          "Value": 990.94
        },

"Date": "2022-10-30T00:00:00",
      "Base": 1173.386,
      "TimeSpans": [
        {
          "TimeSpan": "00:00-01:00",
          "Value": 1030.94
        },
        {
          "TimeSpan": "01:00-02:00",
          "Value": 1009.4
        },
        {
          "TimeSpan": "02:00-02:00",
          "Value": 1006.71
        },
        {
          "TimeSpan": "dst",
          "Value": 1003.41
        },
        {
          "TimeSpan": "03:00-04:00",
          "Value": 984.24
        },
        {
          "TimeSpan": "04:00-05:00",
          "Value": 985.68
        },
        {
          "TimeSpan": "05:00-06:00",
          "Value": 990.94
        },

I'm using NodaTime to try and handle this. I parse a DateTime object using the Date and the second half of the TimeSpan, but this way I always end up with a double instance of 2022-10-30T02:00:00, and this will always be converted to 2022-10-30T01:00:00 UTC. What I need is for the first instance to become 2022-10-30T00:00:00 to be correct in UTC terms. Anyone have any smart ideas?

5 Replies

Unknown User•2y ago

Message Not Public

garrus_jOP•2y ago

public static DateTimeOffset ConvertCETToUTC(this DateTime cetTime)
    {
        // var timeZoneInfo = TimeZoneInfo.FindSystemTimeZoneById("W. Europe Standard Time");
        //
        // bool isDST = dateTimeCET.IsDaylightSavingTime();
        // DateTimeOffset dateTimeOffsetUTC = TimeZoneInfo.ConvertTimeToUtc(dateTimeCET, timeZoneInfo);
        
        var cetInstant = Instant.FromDateTimeUtc(cetTime.ToUniversalTime());
        var cetZone = DateTimeZoneProviders.Tzdb["Europe/Berlin"];
        var cetZoned = new ZonedDateTime(cetInstant, cetZone);

        var utcZoned = cetZoned.ToInstant().InUtc();

        DateTime utcTime = utcZoned.ToDateTimeUtc();

        return utcTime;
    }

thats what I've got so far, it works, but obviously it can't differentiate the first and second instance of 2am on that date

Unknown User•2y ago

Message Not Public

garrus_jOP•2y ago

It is a full DateTime object, which is the Date in the json plus the second hour of the timespan joined together. So 2022-10-30T00:00:00 plus 01:00 would be the first item, or 2022-10-30T01:00:00 Because I want the end of every hourly period to be a full datetime object in the database. I don't know why the api doesnt just deliver it that way

Accord•2y ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ DateTime help with NodaTime