People are confused as to how to sit shiva and how to properly pay a shiva call. Because people do not know, and because talking about death makes people nervous and awkward, the shiva house often turns into a festive gathering filled with nervous chatter, instead of the proper house of mourning.
The average number of days in a month is around 30.4. With 24 hours in a day, this is an average of about 730 hours per month.
In a cycle, there are 7 x 400 = 2800 months of 31 days, there are 4 x 400 = 1600 months of 30 days, there are 300 +3 = 303 months of 28 days, and there are 100 - 3 = 97 months of 29 days. Taking the weighted mean, the average number of days in a month is (2800 x 31 + 1600 x 30 + 303 x 28 + 97 x 29) / 4800 = 30.436875 days exactly.