How do I fix incorrect data?
On the web version, you can update the incorrect datapoint in the Data tab below the graph, then press the Update button.
On Android, you can edit datapoints by tapping on the bulletpoint list icon at the top right, and then tapping the entry you want to edit. Make your change, and then tap Update.
On iOS, tap the datapoint in the list to open the edit window, make your changes, and then tap Update.
You can also delete datapoints using the Delete button on all platforms, though you should do this with extreme caution. Deleting data may trigger an immediate derailment on your graph, because removing old datapoints can change whether you're on the right side of the bright red line now, due to the cumulative graph. Sometimes you may want to do this on purpose if you realize you should have derailed.
Note that editing data may not always stick! If your goal uses an automatic data source, Beeminder will likely refetch the original data from the data source and overwrite your changes. It's not that we don't trust you (well, possibly that too) but we need a single ground truth for the data so if the autodata source changes, Beeminder updates the data to match. So change the data at the source then click the button on the Beeminder goal page to refresh/refetch it.
Of course, we also know that sometimes device batteries die and you forget to use them and all of that, so just reply to the legit check if there are extenuating circumstances.
Keywords: editing data, editing old data, update data