If there is no benefit to establishing a date in the future, assuming this is an option, let the state establish your filing date. This is often the date the filing is officially received by the state (i.e. Arizona, California, Florida, and others), but sometimes it is the date when the filing is completed (i.e. Maryland, New York, Pennsylvania, Texas, and others). With this in mind, timing here can be an issue as well.
For Example, let’s say you were going to file an LLC in a state like California, which assigns an effective filing date as of the date your filing was received. Considering California Secretary of State is currently taking over two months to complete even the more expedited “in person” filings (see California Filing Status), and requisite $800 franchise tax due four months after the filing date, when you submit your filing will have expensive consequences.
For all these reasons, you should consider what the filing date means to your new entity before submitting your filing to the state.