Julie's daily earnings are $5 x 8 = $<<5*8=40>>40.
Her weekly earnings are $40 x 6 = $<<40*6=240>>240.
Her monthly earnings are $240 x 4 = $<<240*4=960>>960.
Since she was not able to work for a day, her salary will be $960 - $40 = $<<960-40=920>>920.
#### 920