In general, nasal mucus is clear and thin, serving to filter air during inhalation. During times of infection, mucus can change color to yellow or green either as a result of trapped bacteria or due to the body's reaction to viral infection.
As such, there is to be no work done on this day. There are other restrictions, as well. Unless health dictates otherwise, Yom Kippur is observed by a 25-hour fast that begins prior to sunset on the evening before Yom Kippur and ends shortly after nightfall on the day of Yom Kippur. During this time, you are not allowed to consume any food or beverage, including water.
The reversed phi ratio count from December 31, 2015 to January 1, 2015 renders the opposite day count where Yom Kippur on September 23, 2015 approximates the focal point of the phi ratio spiral. This depiction is transposed onto the timeline that is illustrated in the chart.