Mine is also 'Canadian Imperial bank of Commerce'. No validity mentioned.
Logically, anything that has an expiry date does have that expiry date explicitly mentioned or a statement like "valid for 6 months" or an indication like "Best Before...." etc.
Today, I asked ICICI Bank folks that my DD has expired since it was issued 6 months back. They shot back, sir how do you know that your DD has really expired ?. That left me sort of puzzled because at the time of issue the very same bank executive told me that it's valid for 6 months.
If Canadian bank issued DD's of CEC-Inland folks don't expire, question is are our Indian DDs which are payable by the same Canadian banks - actually expiring specially when they too don't have any expiry date mentioned ?.
Problem is that OINP is totally nuts. They are simply throwing back the Drafts at the applicants without even trying to encash them.