Sed says: TWICE. From the Northern Hemisphere perspective: Once on March 20/21 .... sun's rays moving northward, and again on Sept 20/21 with sun's rays moving southward.
Straddling two years, the second of which is a non-leap year, and including the start and end dates in the calculation, there are 140 days between the two dates. Straddling two years, the second of...