Man pages matching name datetime::locale::is_is in section 3pm:

DateTime::Locale::is_IS.3pm.en	debian 10 / libdatetime-locale-perl
DateTime::Locale::is_IS.3pm.en	debian 11 / libdatetime-locale-perl
DateTime::Locale::is_IS.3pm.en	debian 12 / libdatetime-locale-perl