If you don’t have the capacity to worship MAA DURGA for nine days continuously  you can worship for fewer days–
(1)SAPTA-RATRA-7 Days -from 1st day of NAVRATRA to (SAPTAMI) 7th day of NAVRATRA.
(2)PANCH-RATRA- 5 Days -from 5th day of NAVRATRA (PANCHAMI) to 9th day of NAVRATRA (NAVMI)
(3)TRI-RATRA -3 Days -SAPTAMI, ASHTAMI & NAVAMI
(4)YUGMA-RATRA-  2Days -The first (starting day of NAVRATRA) and 9th (last day of NAVRATRA)
(5)EKA-RATRA- 1 Day-Either the 1st day of NAVRATRA OR last day (9th) day of NAVRATRA

It’s only fair to share...