When is a negotiable instrument payable on demand?

Sec.  7.  When  payable  on  demand.  -  An  instrument  is  payable  on demand:
 
      (a)  When  it  is  so  expressed  to  be  payable  on  demand,  or  at sight, or on presentation; or
        
      (b) In which no time for payment is expressed. 

Where  an   instrument   is   issued,  accepted,  or  indorsed   when overdue,  it  is,  as  regards  the  person  so  issuing,  accepting,  or indorsing it, payable on demand.
 

EXPRESSED TO BE PAYABLE ON DEMAND

      An  instrument  is  payable  on  demand  where  it  is  expressed  to  be payable on demand, on sight, or on presentation
      It is payable on demand also when no date of payment is specified
      It  is  payable  on  demand  when  the  time  of  payment  is  left  blank  or unfilled
 

INSTRUMENT ON DEMAND ONLY AS BETWEEN THE PARTIES

      That  after  the  date  of  maturity,  the  instrument  can  no  longer  be negotiated as to make the parties who acquire the instrument after the date  of  maturity  holders  in  due  course  because  they  become  holders thereof  with  notice  that  it  is  already  overdue,  as  this  can  be determined from the face of the instrument itself