HI, My grandparent would like to visit Canada for 3 o 4 weeks. My grandparents do not remember their sibling's birthday. We need this information to fill out application "IMM 5645 Family Information application". My grandpa is 83 years old and my grandma is 76. We want to apply for a regular visa. We asked to other family members but they do not know either. What can we do about it?? Any ideas??