https://datatracker.ietf.org/doc/html/rfc5545
RFC 5545 - Internet Calendaring and Scheduling Core Object Specification (iCalendar)
Internet Calendaring and Scheduling Core Object Specification (iCalendar) (RFC 5545, )
rfcinternetcalendaringschedulingcore
https://dirk.eddelbuettel.com/code/qlcal-r.html
qlcal: QuantLib Calendaring for R
Dirk Eddelbuettel, R, C++, Rcpp
quantlibcalendaring
https://legal.thomsonreuters.com/en/legal/business-development/legal-calendaring-solutions
Legal Calendaring Solutions | Thomson Reuters
Efficiently manage your law firm's appointments and legal deadlines with precision by using Thomson Reuters' comprehensive legal calendaring solutions.
thomson reuterslegalcalendaringsolutions
https://mobiscroll.com/
Advanced calendaring, scheduling, planning and resource management | Mobiscroll
Super flexible event calendar, scheduler and timeline for planning, scheduling and resource management. Use with plain JS, jQuery, Angular, Vue, React.
resource managementadvancedcalendaringschedulingplanning