Time limitations and continuing representation are a constant issue in legal malpractice cases.  When the statute begins to run and how long it may be tolled are sub-issues.  Cordero v Koval Rejtig & Dean PLLC;  2013 NY Slip Op 31893(U) ;  August 8, 2013;  Supreme Court, New York County ;  Docket Number: 113450/11; Judge: Debra A. James gives us a nice discussion of both.

"The statute of limitations for attorney malpractice is three years (CPLR 214 [ 6 ] ) . A claim for legal malpractice accrues when the attorney commits the malpractice, not when the client discovers it (Shumsky v Eisenstein, 96 NY2d 164, 166 [lst Dept 20011). A client’s ignorance of his or her attorney’s misconduct has no effect on when a claim for malpractice accrues (Lincoln Place, LLC v RVP Consulting, 70 AD3d 594, 594-595 [lst Dept, 2010). The accrual of the limitations period may be tolled according to the continuous representation doctrine."
 

"Plaintiff contends that the action accrued on December 5,2008, when his personal injury case  was dismissed, and that he had until December 5, 2011 to sue defendants. Plaintiff relies on case law stating that a legal malpractice claim accrues "when all the facts necessary to the cause of action have occurred and an injured party can obtain relief in court’" (McCoy v Feinman, 99 NY2d 295, 301 [2002] , quoting Ackerman v Price Waterhouse, 84 NY2d 535, 541 [1994]). He argues that, until his case was dismissed, he did not have an action against defendants. Plaintiff misstates the applicable law. Plaintiff had a claim against defendants before his case was dismissed, even if he was ignorant of that fact. Where it is alleged that an attorney negligently let pass the statute of limitations for the client’s action, the claim for legal malpractice accrues upon the
expiration of that statute of limitations (Cohen v Wallace & Minchenberg, 39 AD3d 691, 692 [2d Dept 20071; Baker v Levitin, 211 AD2d 507, 507 [1st Dept.1951)."

"As defendants implicitly point out, Koval’s continuous representation of plaintiff can be imputed to defendants. In Antoniu v Ahearn (134 AD2d 151 [lst Dept 1987]), the plaintiff hired the first attorney and her law firm in 1978. 1981 or 1982, the first attorney left that firm and joined In another firm, where she continued to represent plaintiff. Upon hiring a new attorney, plaintiff fired the first attorney in July 1983. On October 10, 1985, plaintiff began an action against the firm retained in 1978. The court determined that the action against the firm that plaintiff retained in 1978 was within the statute of limitations. The limitations period against that firm was tolled until the first attorney stopped representing the plaintiff. The first attorney’s continuing representation, which
stopped in 1983, was imputed to the firm."