cast(<timestamp> as date)

BigQueryDb2 (LUW)MariaDBMySQLOracle DBPostgreSQLSQL ServerSQLite200520072009201120132015201720192021⊘ 3.5.7 - 3.43.0b✓ 2008R2 - 2022✓ 8.3 - 16⊘ 11gR1 - 21ca✓ 5.0 - 8.0.34✓ 5.1 - 10.11✓ 9.7 - 11.5.8✓ 2.0
  1. See “Caution: Oracle Database” above
  2. Use date(<timestamp>) instead