Find the day in which the difference between the max temperature and min temperature was the smallest. Also report the difference.
return days ;return temperatures of #1 ;return the  highest of #2 for each #1 ;return the  lowest of #2 for each #1 ;return the  difference  of #3 and  #4 for each #1 ;return the  lowest of #5 ;return #1 where #5 is equal to #6 ;return #7 ,  #6
['select', 'project', 'group', 'group', 'group', 'aggregate', 'comparative', 'union']