Photoperiod.txt contains daylength data local to the study site for every day of the study period. Column headings: Year: The year of the study period. Date: The date on which a particular set of data was taken. Ordinal_day: The ordinal date of year. Sunrise: The time of sunrise. Sunset: The time of sunset. Daylength: The number of hours, minutes, and seconds of daylight. DayHours: The number of hours of daylight in decimal format. Please contact Jill Anderson (jta24@uga.edu) with any questions