fix(duckdb): default missing year to 1970 for BigQuery PARSE_DATE/PARSE_TIMESTAMP#7800
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BigQuery initializes any field left unspecified by the format string from 1970-01-01, so a yearless PARSE_DATE/PARSE_TIMESTAMP returns a 1970 date. PR tobymao#7704 taught the DuckDB generator to compensate for this (DuckDB STRPTIME defaults a missing year to 1900) for PARSE_DATETIME via a `default_year` flag, but its siblings PARSE_DATE (-> exp.StrToDate) and PARSE_TIMESTAMP (-> exp.StrToTime) were left unmirrored, so e.g. `PARSE_DATE('%m-%d', '12-25')` transpiled to `CAST(STRPTIME('12-25', '%m-%d') AS DATE)` -> 1900-12-25 instead of 1970-12-25. Set `default_year` on the StrToDate/StrToTime built by the BigQuery parser and apply the same 1970-year prefix in DuckDB's strtodate_sql/strtotime_sql, factored into a shared _strptime_default_year helper. The flag is only set by the BigQuery PARSE_* builders, so other dialects' StrToDate/StrToTime are unaffected. A year already present in the input still wins (DuckDB binds the last %Y match). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
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BigQuery defaults an unspecified year to 1970; DuckDB's STRPTIME defaults to 1900. #7704 taught the DuckDB generator to compensate, but only for PARSE_DATETIME. The symmetric builders PARSE_DATE (StrToDate) and PARSE_TIMESTAMP (StrToTime) were left unmirrored, so a yearless
PARSE_DATE('%m-%d', '12-25')transpiles to DuckDB and returns 1900-12-25 instead of 1970-12-25 — a silent 70-year error.The fix reuses #7704's mechanism: a
default_yearflag set only by the BigQuery PARSE_* builders, applied via the same'1970 ' || ...prefix in DuckDB's strtodate/strtotime. Other dialects are untouched, and an explicit year still wins. Verified both ways on a real duckdb engine (1900 before, 1970 after); full suite 1106 passed.