1/ if you have same date of birth in your educational documents and passport then you can immediately go to NADRA and apply for modification in your date of birth...but they will see your birth certificate because they will enter the same date of birth in your id card which is in your birth certificate.
2/ In Passport Office...In your machine readable passport ...they do not enter the date of birth by their own....the date of birth which is mentioned in your CNIC will automatically come in your passport. Did you offer money to change the date of birth in your passport?
3/ If there is only year....just like 1980 is written in your CNIC....computer in passport office will automatically add 1-1-1980 in your passport. If the date of birth in your CNIC is complete then computer will place the same complete date of birth in your passport which is mentioned in your CNIC.
4/ If in your CNIC the date of birth is not complete and it is like 1980..(only year is written). but in your educational documents your date of birth is complete...just like 5-10-1980 then you can request in the passport office at the data entry stage to add the day(5) and month(10) from your educational documents...
so they will accede to your request and you will have the same date of birth 5-10-1980 in your passport as well.....later you can apply to NADRA for modification...
I don't have any idea about the Embassy officials because I haven't applied to Canadian Embassy before....
If you have provided the ID Card Copy with your passport...then it may be problem for you...but other wise its not a problem...still you can approach to NADRa and request them to modify your date of birth in your id card ....
you can talk to me...and I will explain to you anything you want to know..
I have worked for four years in Immigration and Passport Karachi.
My number is 03003048688...
God Bless You Brother...