Data type mismatch for union all with timestamp and date

Calcite and drill execute different implicit cast when a union all query contains timestamp and date on both right and left hand side but in different order.

select col_tmstmp,col_date, col_boln from `prqUnAll_0_v` union all select col_date, col_tmstmp, col_boln from `prqUnAll_1_v`

limit 0: select * from (select col_tmstmp,col_date, col_boln from `prqUnAll_0_v` union all select col_date, col_tmstmp, col_boln from `prqUnAll_1_v`) t limit 0
limit 0: [col_tmstmp, col_date, col_boln]
regular: [col_tmstmp, col_date, col_boln]

limit 0: [DATE, DATE, BOOLEAN]
regular: [TIMESTAMP, TIMESTAMP, BOOLEAN]

limit 0: [columnNullable, columnNullable, columnNullable]
regular: [columnNullable, columnNullable, columnNullable]