It looks like you are wondering if you have grounds to dismiss this case under the speedy trial rule. Based on what I am reading, my answer would be not quite yet. The initial commencement date would be 90 days from the date of arraignment if one is out of custody, not 90 days from the date of the alleged violation, unless you were arraigned on February 22. It is true that courts do not dismiss under the speedy trial rule very often. There are a number of justifications and exceptions under the court rules that extend speedy trial further than 90 days which make dismissal less common, but it does happen occasionally.
While I don't practice in your state, here is my take on the issue.
When your attorney submits a Motion to dismiss based upon Speedy Trial, it must usually be 90 days after the date of arrest and usually from the date of Arraignment, which is often the same day.
However, where you'll likely have the most problems is when the Court goes to count the days, there may have been adjournments that were taken by your attorney or the Court that will eat into that 90 days. I've had that experience and as a result of one such case, the entire criminal justice system in NY started to insist upon the Defense attorney signing off on a document every time they adjourned the case saying it was at their request. Hence, every one of those adjournments count against the accrual of those important 90 days.
If your court doesn't have a sign off document for each adjournment, then it must be noted in the Court Clerk's minutes book as to whose request the adjournment was at so that a court can later determine how many days go against each party.
While you are correct that a dismissals based upon Speedy Trial issues are rarely given, when you have the 90 days accrued against the DA, the court must dismiss. If they fail to dismiss, then you should appeal the case. Also, be careful to check to see how your Appellate Courts have ruled on whether you can still plead guilty to the charge and retain your right to appeal on the Speedy Trial issue. In NY you are NOT allowed to plead guilty and then so appeal, which means if you want to keep the Speedy Trial issue alive, you must take the case through trial. That makes the stakes higher and the relief that much more important to both sides. But it also gives you a second bite of the apple if you lose at trial.
To follow up on the other 2 answers, the 90 day clock is counted from arraignment. One of the many exceptions to the requirement is that the court will not count days during the time a defendant requests a continuance of a date and also signs a waiver of speedy trial. If you have not signed one, the best thing you can do is wait. If this case does get set for trial, that is the time I would file a motion to dismiss, after objecting to the date and noting that it was set outside the required time.
It is true that cases are rarely dismissed based on a speedy trial rule violation. This was true even before some changes a few years ago giving even greater latitude to the Judge and prosecutor. It seems you already have a lawyer reviewing the specifics of your case and filing the dismissal motion. He/She is in a position to answer you best.
At your service,