How to see website traffic across non-standard date-ranges.

Alexa typically allows you to view 4 different default date spans:
1. 3 Months
2. 6 Months
3. 1 Year
4. 2 Years
... but by manipulating the URL directly, you can modify that to whatever you want, down to 2 days or all the way up to 4 years.
To do this, simply go to the graph you want to see using one of Alexa's default time spans, and then modify the part of the URL that looks like this...
traffic_details?&range=3m
In this range parameter, "d" = day, "m" = month and "y" = year.
Replacing "&range=3m" with "&range=8d" will cause the graph to span for 8 days.