law: Limitation Act, 1963 
  18. Effect of acknowledgment in writing – 
  (1) Where before the expiration of the prescribed period for a
  
  suit or application in respect or any property or right, an acknowledgment of
  
  liability in respect of such property or right has been made in writing signed
  
  by the party against whom such property or right is claimed, or by any person
  
  through whom he derived his title or liability, a fresh period of limitation
  
  shall be computed from the time when the acknowledgment was so signed.
  (2) Where the writing containing thee acknowledgement is
  
  undated, oral evidence may be given of the time when it was signed; but subject
  
  to the provisions of the Indian Evidence Act,1872 ( 1 of 1872), oral evidence
  
  of its contents shall not be received.
  Explanation -  For the purposes of this section, - 
  a. an acknowledgment may be sufficient though
  
  it omits to specify the exact nature of the property or right, or avers that
  
  the time for payment, delivery, performance or enjoyment has not yet come or is
  
  accompanied by refusal to pay, deliver, perform or permit to enjoy, or is
  
  coupled with a claim to set-off, or is addressed to a person other than a
  
  person entitled to the property or ornight;
  b. the word "signed" means signed
  
  either personally or by an agent duly Authorized in this behalf ; and
  
  
  c. an application for the execution of a
  
  decree or order shall not be deemed to be an application in respect of any
  
  property or right. 
  
  
  NOTES - It is not necessary that an acknowledgment within
  
  Section 18 must contain a promise pay or should amount to a promise to pay.
  
  (Subbarsadya v.Narashimha, AIR 1936 Mad.939)
  The above section corresponds to S.19 of the old Act and makes
  
  slight changes.