Clients get the benefit of an extended statute of limitations under the principal of continuous representation.  It arose out of "continuing treatment" in the medical malpractice world.  In legal malpractice, there must be some evidence of a "continuing relationship of trust and confidence" between client and attorney.  Absent that, the statute begins on the day the mistake is made.  That’s what happened in Priola v Fallon  2014 NY Slip Op 03130 [117 AD3d 1489]  May 2, 2014
Appellate Division, Fourth Department. 

"Memorandum: In this legal malpractice action, plaintiff appeals from an order granting defendants’ motion for summary judgment dismissing the amended complaint on the ground that, inter alia, the action was time-barred. Plaintiff contends that Supreme Court erred in granting the motion because the statute of limitations was tolled by the continuous representation doctrine. We reject that contention. "A cause of action for legal malpractice accrues when the malpractice is committed" (Elstein v Phillips Lytle, LLP, 108 AD3d 1073, 1073 [2013] [internal quotation marks omitted]). Here, defendants established that any malpractice occurred, at the latest, in 2003 and thus made a prima facie showing that the action was time-barred (see International Electron Devices [USA] LLC v Menter, Rudin & Trivelpiece, P.C., 71 AD3d 1512, 1512 [2010]). "The burden then shifted to plaintiff[ ] to raise a triable issue of fact whether the statute of limitations was tolled by the continuous representation doctrine" (id.; see Macaluso v Del Col, 95 AD3d 959, 960 [2012]), and plaintiff failed to meet that burden inasmuch as he failed to present the requisite " ’clear indicia of an ongoing, continuous, developing, and dependent relationship between the client and the attorney’ " to toll the statute of limitations (Kanter v Pieri, 11 AD3d 912, 913 [2004]; see Guerra Press, Inc. v Campbell & Parlato, LLP, 17 AD3d 1031, 1032-1033 [2005]). In light of our determination, we do not address plaintiff’s remaining contentions. Present—Smith, J.P., Peradotto, Sconiers and Valentino, JJ."