Robuta

https://www.boost.org/doc/libs/1_67_0/libs/icl/doc/html/header/boost/icl/ptime_hpp.html

https://www.ptime.cz/

https://www.boost.org/doc/libs/1_87_0/libs/icl/doc/html/doxygen/interval_container_library_reference/structboost_1_1icl_1_1size__type__of_3_01boost_1_1posix__time_1_1ptime_01_4.html

https://www.boost.org/doc/libs/1_74_0/libs/icl/doc/html/boost/icl/has_diff_idm46063486101072.html