Select between dates?

[Macamba .]

I am surely a newbee. I have the following statement, with error message:

SELECT `day`,`activity`, SUM(`worked_time`) 
FROM `projects` 
WHERE (`day` BETWEEN CAST(`2017-03-13 00:00:00` AS DATE) 
                 AND CAST(`2016-03-143 00:00:00` AS DATE) )
GROUP BY `day`, `activity`;

#1054 - Unknown column '2017-03-13 00:00:00' in where clause

'2017-03-13 00:00:00' is not a column. 'day' is the column name.