The file stamped date is applied by the court that you file into. If you have any concerns about the date, you will need to contact the court that you will be filing into.
If you have a rejected filing, it is recommended to use the Copy Envelope option found in the Filing History. Copying an envelope can provide a reference to a previous filing done on a prior date. To learn how to fix a rejected filing, click here.
If the court directs you to include the original envelope number, please input the information under Comments to Court, in the filing section (returned envelope number).
If the instructions above are followed, the court does have the option to backdate the filing. It is an action that has to be taken on the court reviewer side of the eFile software.