A title card tells us the date is Tuesday October 28th "of this year" and the calendar in Sabrina's room matches this, but later in a scene in Ms. Wardwell's office the calendar on the wall behind her shows that October 28th is in fact a Sunday this year (2018).
A key scene is filmed in an Apple Orchard. It requires Sabrina to pick an apple off a tree and take a bite out of it. As the vehicle taking Sabrina to the Orchard arrives at the Orchard, rows of Apple trees clearing in bloom are visible. This shows that the scene is filmed in early Spring. As Sabrina walks down a row in the orchard we see trees still in full bloom .. with random mature apples wired onto the trees. A maze on the property is made of hay bales. If this was really autumn, the hay bales would still retain some of their green summer color. These hay bales are solidly tan and rotting away -- stale hay which has been stored all winter.