Category of the listed dates. Accepts one of the following atomic values:
•calendar - Lists all monthly days.
•workdays - Lists all working days within the specified month.
•holidays - Lists all holidays within the specified month.
Country
atom()
Adds country-specific definitions for non-working days. All weekends (Saturdays and Sundays) are considered as holidays unless not specified differently for particular country.
The country code SHOULD be two-letter ISO standard code represented as an atom value.