Just applied for citizenship

Hi everyone

I just applied for citizenship and as you know they ask for your parents date of birth which I did but my parents don't know the date and month of their birth but they do know the year is that going to be a problem because I had to make up the date and month

Thank you

It's not an issue.
The reason they ask for parents details is that there are sometimes cases where the applicant is already British, but doesn't know it (yes it does happen!). The parents' details may provide evidence for this.