v.22.5Improvement

Now date time conversion functions saturate to zero for pre-1970 timezones

Now date time conversion functions that generates time before 1970-01-01 00:00:00 with partial hours/minutes timezones will be saturated to zero instead of overflow. This is the continuation of https://github.com/ClickHouse/ClickHouse/pull/29953 which addresses https://github.com/ClickHouse/ClickHouse/pull/29953#discussion_r800550280 . Mark as improvement because it's implementation defined behavior (and very rare case) and we are allowed to break it. #36656 (Amos Bird).
Date and time conversion functions generating timestamps before 1970-01-01 00:00:00 with partial hours or minutes timezones now saturate to zero instead of overflowing.

Why it matters

This feature fixes overflow issues in date time conversions for timestamps prior to the Unix epoch when using timezones with partial hour or minute offsets. It ensures more predictable and stable behavior in these rare edge cases by saturating values at zero instead of producing incorrect overflows.

How to use it

No specific user action is required as this change applies automatically to date and time conversion functions. When converting dates before 1970-01-01 00:00:00 with partial hour/minute timezones, the output will now be safely saturated to zero.