Obviously the End of the Season

How do I know this? Because of the "this day in Disney history" message I read every morning. Once the Holiday crowds go home, it's okay to start closing things:

1977: Mine Train closes at Disneyland Park.
1989: If You Could Fly closes in the Magic Kingdom Park.
1989: Last day of operation of Sunkist Citrus House at Disneyland Park.
1994: Kitchen Kabaret closes at Epcot.

And just to show Disney's 15-month years aren't something new:

1964: "Disneyland�s 10th Anniversary" TV special.

Note that Disneyland's 10th anniversary would have been July 1965, a full 18 months after this TV special aired. Perhaps they meant the 10th anniversary of the TV show, which started in 1954.