Calculation code comments

• Monkey patched date class
• Main calculator controller

Scrutiny end date calculators

• Calculation for bicameral instruments with both Houses sitting
• Calculation for bicameral SIs with either House sitting
• Calculation for Commons only SIs
• Calculation for PNSIs
• Calculation for treaty periods A and B
• Calculation for Commons only sitting days

Scrutiny start date calculators

• Calculation for bicameral instruments with both Houses sitting
• Calculation for bicameral SIs with either House sitting
• Calculation for Commons only SIs
• Calculation for PNSIs
• Calculation for treaty periods A and B
• Calculation for Commons only sitting days