When using standard Teradata Database system time zone strings, no time zone rules are enforced for the years 1986 and before, for example, daylight saving time (DST) shifts. Valid years for Teradata Database standard time zone strings are 1987 through 9999.
If Teradata Database standard time zone strings do not meet your requirements, you can add a new custom time zone string or modify an existing string by modifying or adding new rules to GetTimeZoneDisplacement.