I think you can use my code to solve it, see inside 回複：SAS編程：請賜

來源: 於 2008-04-27 20:52:44 [舊帖] [給我悄悄話] 本文已被閱讀：次

Assuming 日期重疊次數 means the # of same startdate and enddate

proc freq data=datset1;
by ID;
Table startdate/out=outdatset2;
run;