Incorrect change in System time

Hi all, I have written my own rule for customized timezone.The user will provide start and end time for the DST settings.According to that the rule will change and timezone is compiled using "zic". Problem: The Program works fine for all other days.When i give the start time as 2003 jan wed 00:03 and end time as 2003 dec tue 22:05.When i changed my system time to 2003 jan 1 00:00, the system time immediately changed to 22:00.This is not expected behavior as it should change time only on 00:03. When i checked the localtime using "zdump" the "DST" is off for 2003. Kindly help me. Kindly excuse me if anything is wrong on the above mail as i am new to the group. Regards, Purusothaman R