2018 New York Laws
GOB - General Obligations
Article 17 - Revival or Extension; Waiver of Defense or Bar
Title 1 - Obligations Barred by Statutes of Limitation
17-105 - Promises and Waivers Affecting the Time Limited for Action to Foreclose a Mortgage.

§ 17-105. Promises  and  waivers affecting the time limited for action
  to foreclose a mortgage. 1. A waiver  of  the  expiration  of  the  time
  limited  for  commencement  of an action to foreclose a mortgage of real
  property or a mortgage of a lease of real property, or a waiver  of  the
  time  that  has expired, or a promise not to plead the expiration of the
  time limited, or not to plead the time that has expired, or a promise to
  pay the mortgage debt, if made after the accrual of a right of action to
  foreclose the mortgage and made, either with or  without  consideration,
  by  the  express terms of a writing signed by the party to be charged is
  effective, subject to any conditions expressed in the writing,  to  make
  the time limited for commencement of the action run from the date of the
  waiver  or  promise. If the waiver or promise specifies a shorter period
  of limitation than that otherwise applicable, the time limited shall  be
  the period specified.
2. a. A statement by a grantee of real property or assignee of a lease
  of  real  property,  effective under section 5-705 of this chapter as an
  assumption of or agreement to pay an indebtedness or other  sum  secured
  by  a  mortgage of such property or lease has also, to the extent of the
  amount specified therein, the same effect as provided  in  this  section
  with respect to a waiver or promise described in subdivision one, unless
  it  contains  language disclaiming an intention to affect the statute of
  limitation.
b. A recital, in an instrument in which real property is conveyed or a
  lease is assigned, that the conveyance or assignment is made subject  to
  a  mortgage,  or  provision to that effect in a contract for purchase of
  real property or purchase of a lease, or an agreement or  instrument  by
  which  another  encumbrance or interest is subordinated to the lien of a
  mortgage, does not have the effect provided in this section with respect
  to a waiver or promise described in subdivision one.
3. A waiver or promise made as provided in this section is effective
a. against (1) the person who made it, to the extent of  any  interest
  held  by  him  at  the  date  thereof  and  (2)  any person subsequently
  acquiring from him any such  interest,  without  giving  value  or  with
  actual  notice  of the making of the waiver or promise, to the extent of
  the interest so acquired; and
b. in favor of (1) the mortgagee or his assignee, (2) any other person
  to whom or for whose benefit it is expressed to be  made,  and  (3)  any
  person  who,  after  the making of the waiver or promise, succeeds or is
  subrogated to the  interest  of  either  of  them  in  the  mortgage  or
  otherwise acquires an interest in the enforcement of the mortgage.
4.  Except  as provided in subdivision five, no acknowledgment, waiver
  or promise has any effect to extend the time limited for commencement of
  an action to foreclose or mortgage for any greater time or in any  other
  manner  than  that  provided  in  this section, nor unless it is made as
  provided in this section.
5. This section does not change the requirements, or the  effect  with
  respect to the time limited for commencement of an action, of
a.  a  payment or part payment of the principal or interest secured by
  the mortgage, or
b. a stipulation made in an action or proceeding.
6. The term "real property" as used in this section is co-extensive in
  meaning with lands, tenements and hereditaments.