The calendar provides a way to easily see the strength of the market as well as provide links to past daily reports.  

Accumulation / Accumulation with Confirmation

Accumulation days are indicated in green and signals buying by institutions - a sign of a strong market necessary for starting and sustaining rallies. 

Accumulation days with confirmation will be marked in yellow.  These days are necessary for the start of a new rally and occurs when any major index rises 2% or more on heavier volume than the day before.  Not all confirmed rallies lead to a new bull market, but no new bull market can begin without one. 

See more on confirmation in the tutorial here.

Distribution

Distribution days are indicated in red and signals selling by the institutions - a sign of weakness.  3-5 days of distribution over the course of a couple weeks can derail a rally. 

See more on distribution and market direction here.