Order unanimously affirmed without costs. Memorandum: Plaintiff's claim against defendant school district accrued on December 30, 1989, the date payment was due from defendant and, consequently, the date upon which plaintiff's damages were "ascertainable" (Matter of Board of Educ. [Wager Constr. Corp.], 37 N.Y.2d 283, 290). Plaintiff's notice of claim would be timely if it was mailed by March 30, 1990 (see, Matter of Central School Dist. No. 1 v. Double M. Constr. Corp., 41 A.D.2d 771, 772, affd 34 N.Y.2d 695). Because the date the notice of claim was mailed cannot be ascertained from this record, this issue cannot be resolved on defendant's motion for summary judgment.