使用预定义过滤器过滤SQL查询

I've pasted my code below. What I'm trying to do is filter a set of data using the day. The 'day' field is stored as the abbreviated day name, so "thu" for Thursday etc. This works perfectly fine, except once you've changed the date filter to something else, the option for the current day doesn't work.I've pasted my code below. What I'm trying to d