Days of the week formatting in alphabetical order

I have a column chart that when drilled down displays data with the axis being the days of the week, like this:

However, as you can see, it is sorting the days by alphabetical order rather than by the days of the week. By the way, this is how the chart looks before it is drilled down:

The days of the week exist as a calculated column with the following DAX expression:

Weekday = CONCATENATE(sometable[Day], SWITCH(WEEKDAY(sometable[datetime]), 1, ": Sun ", 2, ": Mon ", 3, ": Tues ", 4, ": Wed ", 5, ": Thurs ", 6, ": Fri ", 7, ": Sat "))

where [Day] is the integer from 1-31 representing the days of the month.

I was hoping that the drill down format would just follow the format of the original, but it doesn't seem to work that way. Also to note is that I am using DirectQuery, so I have those limitations. Anyone have a solution to this issue? Thanks for the help.