Daily Average Calculation seems wrong.
Hi,
I don't know why really. Why is there seems a difference between daily average that calculated with .csv file that has exported directly from the channel.
and calculation with the ThingSpeak Daily Average API, there is a lot of difference at the moment.
Why does this happens, and how should I fix this issue?
Attached image file is daily average that has been retrived through the API,
And attached excel file is raw data from the channel.
Thank you.
2 Comments
Time Descending
This difference usually happens because of how the daily average is grouped and calculated internally by the API compared to a manual Excel calculation from the CSV file.
In many cases, the issue is related to:
- Time zone settings (UTC vs local time)
- Grouping by full timestamp instead of just date
- Missing or irregular data intervals
- How null or empty values are treated
The ThingSpeak Daily Average API may group data strictly based on the channel’s configured time zone, while Excel might be calculating based on your system’s local time. Even a few hours’ difference can shift values into another day and change the average noticeably.
I would suggest manually taking one single day of raw data, grouping it strictly by date, and calculating the average step by step to compare both methods. That usually makes the difference clear.
I often read technical blog discussions about time-series calculations, and most differences like this come from boundary grouping logic rather than incorrect data. So this is very likely a calculation alignment issue rather than an API error.
Hope this helps you sort it out
Often the issue is the time zone for the calculation. ThingSpeak may be using GMT for the daily calculation.
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