With October upon us, students at the College eagerly await an early-morning email from President Maud S. Mandel announcing Mountain Day — the annual cancellation of classes for Williams Outing Club hikes, a cappella performances, and cider donuts on one of the first three Fridays of the month. While obsessively checking weather forecasts and “rouletting” the night before, students spew countless theories about the logic behind Mandel’s decision. What can history tell us about Mountain Day trends?

Over the last 15 years, Mountain Days have fallen on each week at the following rates:

First Friday — 47 percent

2010, 2011, 2012, 2014, 2016, 2018, 2021

Second Friday — 33 percent

2017, 2019, 2020, 2022, 2023

Third Friday — 20 percent 

2009, 2013, 2015

Although some students hoped to have the day off last week, the first Friday is now off the table. But the second and third are still up for grabs — and if Mountain Day isn’t this Friday, it will be the first time it has fallen on the third Friday since 2015.