The Minnesota Rules of Criminal Procedure Rule 22.03 does not prescribe a time frame for which a subpeona must be served prior to an appearance before the court, deposition or grand jury.
Failure to appear for a subpeona that has been served upon you results in a finding that you are in contempt of court and a warrant could be issued for your arrest.
Depending on the length of trial, you may be able to contact the party who subpeonaed you to attempt to change the date of your appearance if it is a hardship to you. Make sure if you are able to change your appearance date that you get it in writing.
The information contained in this answer does not result in an attorney-client relationship or an ongoing obligation to answer your question. Please understand that this answer does not constitute legal advice and that each situation is unique and facts that pertain to your situation may change the answer provided.
I am not aware of any legal requirements of a time frame for serving a subpoena ahead of the date of appearance. It is a fundamental Constitutional right essential to the court's search for the truth in a trial; and such a requirements could result in injustices. As a trial lawyer, I make efforts to serve a subpeona a couple weeks or so ahead of time, as a practical matter, in order to provide what seems like reasonable notice.
If a witness wants to legally challenge a subpoena they can do so with or without a lawyer's help, by making a motion to quash.
Usually the date and time on the subpoena is a ballpark guess as to when the witness will need to testify. If the witness is cooperative, most lawyers and courts issuing supboenae will work with the witness to reduce inconvenience.
There is not a time frame set out by case law or a statute. However it is not uncommon for subpoenas to be served days or the day before a trial. I have always tried to let witnesses know well in advance of trial if they will be needed. There are times though where the prosecutor will not subpoena one of their own witnesses. As a result I have to serve subpoenas on the entire prosecution witness list. This may not occur until two days before trial.
It really depends on how the prosecution tries to negotiate plea agreements. These situations only occur with prosecutors who will not "blink" so to speak until a few days before trial. If there are last minute subpoenas they still must be followed. Depending on the county, they may send law enforcement to pick you up if you fail to appear. In the alternative they may issue a warrant.