```ruby
class DateTime

  # Returns a DateTime range of the past 7 days
  def self.this_week
    (DateTime.current - 7.days)..DateTime.current
  end
  
end
```

Update 'this_week' to use beginning/end of day and proper time zones
user
```ruby
class DateTime

  # Returns a DateTime range of the past 7 days. 
  # Goes from midnight (start of day) to midnight (end of day), covering a 7-day stretch
  def self.this_week
    (DateTime.current.in_time_zone.beginning_of_day - 6.days)..DateTime.current.in_time_zone.end_of_day
  end
  
end
```
assistant