The time zone is not stored in the rows of the table,
but is stored in the column metadata.

From ClickHouse documentation
https://clickhouse.com/docs/en/sql-reference/data-types/datetime

The point in time is saved as a Unix timestamp, regardless of the time
zone or daylight saving time. The time zone affects how the values of
the DateTime type values are displayed in text format and how the values
specified as strings are parsed (‘2020-01-01 05:00:01’).

Timezone agnostic Unix timestamp is stored in tables, and the timezone
is used to transform it to text format or back during data import/export
or to make calendar calculations on the values (example: toDate, toHour
functions etc.). The time zone is not stored in the rows of the table
(or in resultset), but is stored in the column metadata.

TIMESTAMP(p)
TIMESTAMP(p) WITH TIME ZONE