It is not up to the District Attorney to decide if a hearing will be continued (although it helps a great deal if he or she does not object), that is up to the judge to decide. The only way that a party can get their presence waived or a hearing continued is with permission from the court. The court won't spontaneously decide to do those things without a motion from the party stating the reasons for the need to continue. If someone is running out of time to get a court to make a ruling, they need to file either an "expedited motion" or an "emergency motion". However it is important to beware the court will frown on last minute motions.
The proceeding statement is for your benefit and designed to orient you to seek help more completely; it should not be construed as a complete answer to your legal problem or a substitution for legal advice. Only when an attorney has had the opportunity to fully explore the issues of your case can you truly be advised. By reading my statement you should not infer we have created an attorney client relationship.
At this point in time, you will probably need to appear at sentencing. You can try calling the Court and explaining the situation. You have nothing to lose by trying.
Why do you want to continue the hearing. Is it because you will be in surgery or because you are concerned that you will be sentenced to jail and will be unable to get your surgery before going to jail.
If you are concerned with being sentenced to jail and thus unable to get surgery, bring a note from your doctor, along with your doctors name a phone number and explain your situation to the judge. The judge may give you time to get surgery and recover before sending you to jail.
Legal disclaimer: We at the Joffe Law FIrm wish to help you. While the above answer is intended to provide general information only, does constitute legal advice, and does not create an attorney client relationship, we strongly suggest that you seek legal counsel.