function Data = import_data(filename, latitude)
% IMPORT_DATA Read in data from a CSV file.
Data = ezread(filename);

% Convert date column to day_of_year, year columns
datev = datevec(Data.date);
Data.date_year = datev(:,1);
Data.date_day = date2doy(datenum(datev));

% Add an hours of darkness column
Data.hod = hoursdarkness(Data.date_day, latitude);
