please help me. i stuck with this problem for weeks. M T W Th F S Su M T W Th F S Su 1 2 3 4 5 6 7 8 9 10 11 12 13 14 A D D X X N N XR X D D X XR N N B N N X X D D XR X N N X XR D D C X X D D XR X N N X XR D D X X D X X N N XR X D D X XR N N X X M-Monday, T-Tuesday, W-Wednesday, Th-Thursday, F-Friday, S-Saturday, Su-Sunday there is 4 teams called A, B, C, D the shift pattern follow the pattern "DDXXNNXX" which is 2 day shift follow by 2 rest day follow by 2 night shift. and then after that the pattern repeated. i was able to generate the results properly but it is just for a year. i need the results which should be generated continuously. thanks in advance for your helps. the rule is the 3rd X (rest day) should be the oncall shift(XR), which run through the calender. if team A is D shift then team B should be N shift. if team A and B is working day (regardless shift) then Team C and D will be rest day (X). my friend did suggest me to use array but i'm not so good using array functions.