Fix timestamp mismatch

[RyanL1997]

Ryan's brain dump for the problem

First you got a function in the src/plugins/home/server/services/sample_data/routes/install.ts to update the log timestamp to current time

  // Function to update timestamps
  function updateTimestamps(doc: any) {
    dataIndexConfig.timeFields
      .filter((timeFieldName: string) => getNestedField(doc, timeFieldName))
      .forEach((timeFieldName: string) => {
        const timeValue = getNestedField(doc, timeFieldName);
        const updatedTime = dataIndexConfig.preserveDayOfWeekTimeOfDay
          ? translateTimeRelativeToWeek(timeValue, dataIndexConfig.currentTimeMarker, nowReference)
          : translateTimeRelativeToDifference(
              timeValue,
              dataIndexConfig.currentTimeMarker,
              nowReference
            );
        setNestedField(doc, timeFieldName, updatedTime);
      });
    return doc;
  }

In the Current Logic:
The function src/plugins/home/server/services/sample_data/lib/translate_timestamp.ts calculates the difference between source and sourceReference, and then applies that difference to targetReference:

// Translate source timestamp by targetReference timestamp,
// perserving the distance between source and sourceReference
export function translateTimeRelativeToDifference(
  source: string,
  sourceReference: any,
  targetReference: any
) {
  const sourceDate = iso8601ToDateIgnoringTime(source);
  const sourceReferenceDate = iso8601ToDateIgnoringTime(sourceReference);
  const targetReferenceDate = iso8601ToDateIgnoringTime(targetReference);

  const timeDelta = sourceDate.getTime() - sourceReferenceDate.getTime();
  const translatedDate = new Date(targetReferenceDate.getTime() + timeDelta);

  return `${dateToIso8601IgnoringTime(translatedDate)}T${source.substring(11)}`;
}

If sourceReference and source are not on the same date, the time difference between them gets added when translating to the targetReference, potentially introducing an unintended shift. Since the source in the log is 2024-10-16 (you can console log it), and the sourceReference in code you setup is 2024-10-15 so that, in your case, the time delta is 1 day. These two days will be added into the targetReference, for the query we tried so that it is the now for your machine's local time. The return of the function will be now + time delta, which will be 1 days in the future. Thats explained why when I installed it at midnight of OCT 17 it shows OCT 18 in index timestamp.

Solution: Set sourceReference to the Same Date as source

If our goal is to maintain the same date for source during the translation, then setting sourceReference to the same date as source would prevent any additional time from being added. Thats why I made this commit, so that the currentTimeMarker as the sourceReference matches what you got in the log. - You can try out by console log every single line in translateTimeRelativeToDifference() with/without my change.