Question: how many days are there in a year excluding sundays?
Answer: Most years have 365 days, but a leap year has 366 days. That adds up to 52 weeks (where each week is exactly 7 days) PLUS 1 or 2 additional days. The year 2020 has exactly 366 days. Now if the year starts on a Sunday in a non-leap year, you end up with 53 Sundays.