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What timestamp are displayed in CDF?

  • 14 June 2024
  • 3 replies
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The information I found here is contradictory: Cognite Hub

Specifically, I am interested in Aker BioMarine’s tag data on CDF (example shown below).

 

I did not check the documentation, since I prefer to hear it here, “straight from the horse’s mouth”, if you will.

Questions:

  • Is the same time zone used for all of our assets, regardless of location of the geographic location of our manufacturing site?
  • Is the time stamp preserved for time series downloaded using, e.g., Python / Jupyter notebook?
  • Anything else I should be aware of?

Thank you very much!

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Best answer by Glen Sykes 17 June 2024, 19:47

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Userlevel 3

Hi Patrick,

I can confirm that all data point time stamps are stored in CDF as UTC, any offsets applied in the charts application are done so locally in the client application and do not affect the stored data.

What might be of interest to you is a Time Series API feature we released in our June 5th release that allows users to specify a named time zone (according to those zones defined in the IANA database) in which to retrieve the data.  When a time zone is specified, the API applies the appropriate offset to the timestamps of the data points in order to return the correct selection of data.  The feature works for all named time zones, including those with a 15 minute offset such as Nepal.
 

The feature also allows API users to explicitly specify the time offset, in 15 minute increments, if required.

In conjunction with time zone support, we have also introduced support for monthly aggregate granularity.  This feature adds a new ‘month’ time granularity parameter option in addition to second, minute, hour and day. Users can specify an aggregate bucket size from 1 month to a theoretical maximum of 100,000 months.  When retrieving aggregated data, the API will automatically return aggregated values for the month(s) contained within the query, and will automatically account for the number of days in the month, including leap years, and including daylight savings time adjustments.

We plan to introduce functionality to select your preferred time zone in which to display your data to relevant applications and user interfaces in future releases.  

 

Userlevel 3

I forgot to link to the relevant API guide page, if that’s of interest.

https://api-docs.cognite.com/20230101/tag/Time-series/operation/getMultiTimeSeriesDatapoints

And the guidance page on how to use Time Zones is here
https://developer.cognite.com/dev/concepts/aggregation/calendar/

Kind Regards, Glen 

@Glen Sykes, thanks, I appreciate it.

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