'calendar-related' originates from the word 'calendar,' which comes from the Latin word 'calendarium,' meaning 'account book,' and the suffix '-related,' indicating a connection or association.

'Calendar' evolved from the Latin 'calendarium' through Old French 'calendier' to the modern English 'calendar.' The suffix '-related' is a modern English formation.

Initially, 'calendar' referred to an account book, but over time it evolved to mean a system for organizing days.