(a) For the purpose of this section:

1. (1) Epidemic shall mean health-related conditions which adversely affect the attendance of pupils enrolled in the schools of a district, the duration of which shall be determined by the school physician or the health officer for the locality in which such school district is located, provided that, on one or more successive school days during such period, such conditions cause a decrease in the actual pupil attendance of eight percent or more below the ratio of actual attendance to possible attendance for the corresponding day or days in any one of the prior three school years.
2. (2) Manmade or natural disaster means the occurrence or imminent threat of widespread or severe damage, injury, or loss of life or property resulting from any manmade or natural causes, other than an act of terrorism, such as fire, flood, earthquake, hurricane, tornado, high water, landslide, mudslide, windstorm, wave action, epidemic, air contamination, drought, explosion, water contamination, chemical accident, war or civil disturbance.
3. (3) Act of terrorism shall mean such term as defined in subdivision (1) of section 490.05 of the Penal Law.

(b) A school district may exclude from its average daily attendance, student attendance for those days during the existence of an epidemic, manmade or natural disaster, or act of terrorism upon the approval by the commissioner of an application by the district to exclude such days. An application for such purpose shall contain the following:

1. (1) the day or days for which exclusion is sought;
2. (2) the actual attendance on such day or days;
3. (3) the actual attendance on a corresponding date in any of the prior three school years;
4. (4) a written statement by the school physician or public health officer of the locality in which the school district is located as to the existence of an epidemic within such school district, and the beginning and ending dates of such epidemic; and
5. (5) such other information as the commissioner may require.