What are consecutive calendar months (cons.cal.months) in filters?

In filters, you can select Months but also Consecutive Calendar Months as a time period. What is the difference? Consecutive calendar months means “from today to the end of the month of the last month of the period.”

Let's consider the following example given by the FAA:

if an airport operator is subject to an FAA periodic inspection (annual airport inspection) on January 15, 2010, “twelve consecutive calendar months” will end on January 31, 2011. If an airport operator is subject to an FAA periodic inspection on January 28, 2010, “twelve consecutive calendar months” will end on January 31, 2011.

What do I need cons.cal.months for?

The notion of consecutive calendar months is used by official authorities, e.g. to enforce flight limits, such as the EASA limit of 1000 flight hours in 12 consecutive calendar months. With RB Logbook, you are able to track this limit by creating a filter statement that includes consecutive calendar months as the time indicator.