I had more than 95 trips to the US in the last 2 years. It was gonna make my application really lengthy if i mention all . So I mentioned latest entry and in the ‘reason section’ I explained that i have crossed border many times and returned on the same day.
I don't know if it will be a problem, but they clearly asked applicants to list ALL absences no matter how long, or reason.
https://eservices.cic.gc.ca/rescalc/redir.do?redir=faq#Q7
Q7: Do I have to declare day trips to the United States?
A7: Yes. List all absences, even if you come back
the same day.
Q8: I travel often to the United States and don't remember the exact dates. What do I do?
A8: To use the physical presence calculator, you must enter exact dates. Check your passport and other records like: banking records, travel itineraries and receipts to help you determine your dates of travel.
Q9: I travel often because of my work (truck driver, employee for an airline company, etc.). Do I have to declare those absences?
A9: Yes. All absences from Canada, regardless of the reason, must be declared.
Q10: Do I need to declare absences prior to becoming a permanent resident?
A10: Yes, all absences from Canada during your eligibility period, the five (5) years preceding the date of your application, must be declared. Therefore your absences during your time as a temporary resident or protected person within the eligibility period must be declared as well.