Weekly Period Separator [Adjustable History]

Features:
Adjustable History: Shows weekly separators for a configurable number of weeks back (1-100 weeks)

Customizable Appearance:

Choose line color, width, and style (solid, dotted, dashed)

Defaults to showing 10 weeks of historical data

Accurate Week Detection: Properly handles week boundaries regardless of timezone

Clean Implementation: Uses lines that extend from bottom to top of chart