
The irregularity in the number of days per month
is a real disadvantage for the economy and especially for all the statistics.
For example, an absolutely equal capacity results in deviations of around 30% (plus 16% to minus 14%) in the turnover of a company or for the occupation of a clinic.
One can neither compare months nor quarters, halfyears nor years. So, for example, the percentages for the projection of the 5 wise men for modifying the gross domestic product lie in the region of 23% within the error rate of the differing actual working times, from –1,20 to +2,02 = 3,22%!
The following diagram shows the three months January, February and March.


