But then on CIC website, they asked us to put * for unknown day or month where applicable, and leave the form unvalidated. I'm very confused.Thank you!! Just an update, I called CIC this morning and was advise that I could put anydate if his birthdate is unknown but to provide and written explanation with the application package. Apparently a lot of people is having trouble with the form not validating because it won’t accept the (*). So I asked if I could put the date as 1900-01-01 and was told yes I could in order to get the form validated just provide a written explanation as to why.
"Enter your date of birth. If you do not know your complete date of birth, please use an “*” (asterisk) to fill in the spaces for the unknown year, month or day. For example, if the day and month of your date of birth is unknown you could enter 1964/*/*."
"Note: If you do not know the complete date of birth or if the date is in the 1800s, please use a “*” (star sign/asterisk) to fill in the spaces for the unknown year, month or day. The missing information can be added by hand however the form cannot be validated."
https://www.canada.ca/en/immigration-refugees-citizenship/services/application/application-forms-guides/guide-5772-application-sponsor-parents-grandparents.html