A blood blister forms when skin and small blood vessels are damaged without breaking the skin. Trapped beneath the skin surface is some blood and skin fluid. Blood blisters are commonly caused by accidents in which the skin is pinched by a tool or a heavy weight, or they may occur from constant rubbing back and forth.
1 Sunshine hours in Chicago, Illinois range between 3:42 per day in December & 10:14 for each day in July. 2  The longest day of the year is 15:02 long and the shortest day is 8:57 long.  The longest day is 6:04 longer than the shortest day.
When is the longest day of the year? The longest day and the shortest night of the year in the Northern Hemisphere occur during summer solstice which is usually observed on june 21st or sometimes on june 20 UTC (see table 1). In 2016 summer solstice is observed on june 20th, exactly at 22:34 UTC. This is also the day of the shortest day and the longest night in the Southern Hemisphere. The opposite case takes place during december solstice - the shortest day and the longest night occur in the Northern Hemisphere and the longest day and the shortest night are observed in the Southern Hemisphere.