Calculation of interview time

Dear Community,

We completed a multi-country survey. The in the form I had included the meta-data but did not include “audit”.

I am using “start” and “end” to calculate the duration of interview. Is it correct?
Keeping the following definitions in mind:
start: interview start time
end: interview end time
today: the day when interview was conducted
_submission_time: time when interview was uploaded to the server

Using “end” - “start” = length of interview

one of the output is negative and several interviews length are in hours! while it should have taken only minutes to do. Am I missing anything?

Thank you for your insights.

Hi @ssp, welcome back to the community!

Following information is from the help article, Form Settings and Metadata — KoboToolbox documentation

Metadata Description
Start Time Date and time when opening the form (timestamp)
End Time Date and time when finishing the form (“Submit” button pressed)

Both are from the client side.

The submission_time is from the server side.

Some users have experienced similar “problems” with the accuracy of start and end times. So the accuracy of these time indicators are debatable / depending on your approach.

Kal provided some approaches before, if you want to check those:


Thank you @hakan_cetinkaya. The survey is completed now. So, going back to form building is not an option.

I am worried about how to best interpret this information without any bias or at least being able to highlight all the biases. @Kal_Lam Can you please confirm how accurate is the start and end metadata?


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The Collect android app captures the metadata variables automatically from the device during the time of data collection (date captured at the client side as stated by @hakan_cetinkaya). Hence, it is important for the device to have the correct date and time during data collection. If this date and time are distorted (in the device), the app will capture the same. Hence, the user should be cautious when collecting meta data information.

As a check, you could distort the date and time and make a submission to the server. You should see how it behaves.

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Thank you @Kal_Lam.

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Further hint:
End time will change when you edit the case, also after submission on server level! (At least if you edit with modal option. I am not sure how bulk edit behaves here.)

End is the datetime of the last save, this may be equal, before or after the submission_time.

General hint: Test also data export and analysis demands before starting data collection.