For running J!5.1 you must https://fabrikar.com/forums/index.php?wiki/update-from-github/ or include the new file manually https://fabrikar.com/forums/index.php?threads/joomla-5-1-and-fabrik-cannot-find-files-error.54473/post-285151 See also Announcements
Please see our announcement here.
$irrstarthour = $formModel->formData['data_pivot_irrigation___irrigation_start'][0];
$irrstartmin = $formModel->formData['data_pivot_irrigation___irrigation_start'][1];
$irrstophour = $formModel->formData['data_pivot_irrigation___irrigation_stop'][0];
$irrstopmin = $formModel->formData['data_pivot_irrigation___irrigation_stop'][1];
$irrstart = ($irrstarthour * 60) + $irrstartmin;
$irrstop = ($irrstophour * 60) + $irrstopmin;
$irrdec = $irrstop - $irrstart;
$hour = floor($irrdec / 60);
$minb = $irrdec - ($hour * 60);
$min = sprintf("%02d",(int)$minb);
$timediff = $hour . ':' . $min;
$formModel->updateFormData("data_pivot_irrigation___irrigation_duration", $timediff, true);
$irrstarthour = $formModel->formData['data_pivot_irrigation___irrigation_start'][0];
$irrstartmin = $formModel->formData['data_pivot_irrigation___irrigation_start'][1];
$irrstartsec = $formModel->formData['data_pivot_irrigation___irrigation_start'][2];
$irrstophour = $formModel->formData['data_pivot_irrigation___irrigation_stop'][0];
$irrstopmin = $formModel->formData['data_pivot_irrigation___irrigation_stop'][1];
$irrstopsec = $formModel->formData['data_pivot_irrigation___irrigation_stop'][2];
$irrstart = ($irrstarthour * 3600) + ($irrstartmin * 60) + $irrstartsec;
$irrstop = ($irrstophour * 3600) + ($irrstopmin * 60) + $irrstartsec;
$irrdec = $irrstop - $irrstart;
$hour = floor($irrdec / 3600);
$minb = $irrdec - ($hour * 3600);
$minc = floor($minb / 60);
$min = sprintf("%02d",(int)$minc);
$secb = $minb - ($minc * 60);
$sec = sprintf("%02d",(int)$secb);
$timediff = $hour . ':' . $min . ':' . $sec;
$formModel->updateFormData("data_pivot_irrigation___irrigation_duration", $timediff, true);
$minutes = (int) $data['yourtable___duration_total'];
$seconds = $minutes * 60;
$from = new DateTime("@0");
$to = new DateTime("@$seconds");
return $from->diff($to)->format('%h:%i');