org-agenda-start-on-weekday

org-agenda-start-on-weekday is a variable defined in `org-agenda.el'.
Its value is

1

Documentation:
Non-nil means start the overview always on the specified weekday.
0 denotes Sunday, 1 denotes Monday, etc.
When nil, always start on the current day.
Custom commands can set this variable in the options section.

You can customize this variable.