Accounting Calendar defines fiscal period in which the company is working.
It must be registered carefully, so that accounting entries work properly.
Fiscal Period has an year duration and does not have to be the calendar year (1/1 to 12/31), though most of the times it is.
Once defined, this date cannot be changed, except in unexpected circumstances, which do not violate the basic principle of Consistency.
For Income Tax purposes, fiscal period must coincide with calendar year.
They are represented by the beginning and end of a range of dates.
Within a single fiscal year, from 1 to 99 periods can be registered.