The Inca calendar had 12 months of 30 days, with each month having its own festival. The Incan year began in December, and began with Capac Raymi, the magnificent festival.
Gregorian month - Inca month - Translation
January - Camay quilla - Fastening and Penitence
February - Hatun-pucuy - Great Ripening
March - Pacha-puchuy - Earth Ripening
April - Ayrihua or Camay Inca Raymi - Festival of the Inca
May - Aymoray quilla or Hatun Cuzqui - Great Cultivation
June - Inti Raymi - Feast of the Sun
July - Chahua-huarquiz, Chacra Ricuichi or Chacra Cona - Ploughing Month
August - Yapaquis, Chacra Ayaqui or Capac Siquis - Sowing month
September - Coya Raymi and Citua - Festival of the Moon
October - K'antaray or Uma Raymi - Month of crop watching
November - Ayamarca - Festival of the dead
December - Capac Raymi - Magnificent festival