Before going on, would you mind to tell us what you want to do/analyse with the End value?
There was a very detailed discussion about stand, end and _submission_time which can be found with the search function of the forum.
https://community.kobotoolbox.org/t/multiple-submissions-randomly-appeared-all-at-once-on-server-days-to-weeks-after-submitting/31465/11
It seems as the API allows to set/change the start, end values.
https://community.kobotoolbox.org/t/edit-submission-time-via-api-is-it-possible/30768/3
Maybe @josh could give an example how this can be done with the API.
