instruction: Average score by day of post.
response: SELECT (TIME_TO_STR(CreationDate, 'WEEKDA%Y') - 1) * 24 + TIME_TO_STR(CreationDate, '%-HOUR') AS WeekHour, CAST(SUM(Score) AS FLOAT) / CAST(COUNT(Id) AS FLOAT) FROM Posts WHERE PostTypeId = 1 AND Score >= 0 AND Score < 10 GROUP BY (TIME_TO_STR(CreationDate, 'WEEKDA%Y') - 1) * 24 + TIME_TO_STR(CreationDate, '%-HOUR') ORDER BY WeekHour