Hi, I have a question about the code in zic.c. In function stringrule I get: week = 1 + rp->r_dayofmonth / DAYSPERWEEK; if ((week - 1) * DAYSPERWEEK + 1 != rp->r_dayofmonth) return -1; //... week = 1 + rp->r_dayofmonth / DAYSPERWEEK; if (week * DAYSPERWEEK - 1 != rp->r_dayofmonth) return -1; What do these two if check here? The first one passes only when rp->r_dayofmonth mod 7 equals to 1. And the second one passes only when rp->r_dayofmonth mode 7 equals to 6. But IMO rp->r_dayofmonth can be arbitrary valid day number of the month. This question came up with a problem of compiling following input file: #RULE NAME FROM TO TYPE IN ON AT SAVE LTRS Rule localtime minimum maximum - Mar Sun<=14 2:00 1:0 PDT Rule localtime minimum maximum - Nov Sun<=7 2:00 0:0 UTC # ZONE NAME GMTOFF RULES/SAVE FORMAT Zone localtime 0:0 localtime %s zic prints out: "fault.txt", line 6: too many transitions?! (rule from "fault.txt", line 2) After I removed the two if check, this file can be successfully processed. Is this problem caused by a bug in zic.c or the invalid input data. Thanks. Lei