feat: (Preview) Support arithmetics between dates and timedeltas

bigframes/core/compile/scalar_op_compiler.py

@@ -752,6 +752,21 @@ def timestamp_sub_op_impl(x: ibis_types.TimestampValue, y: ibis_types.IntegerVal
     return x - y.to_interval("us")
 
 
+@scalar_op_compiler.register_binary_op(ops.date_diff_op)
+def date_diff_op_impl(x: ibis_types.DateValue, y: ibis_types.DateValue):
+    return (x.delta(y, "day") * UNIT_TO_US_CONVERSION_FACTORS["d"]).floor()  # type: ignore
+
+
+@scalar_op_compiler.register_binary_op(ops.date_add_op)
+def date_add_op_impl(x: ibis_types.DateValue, y: ibis_types.IntegerValue):
+    return x.cast("timestamp") + y.to_interval("us")  # type: ignore
+
+
+@scalar_op_compiler.register_binary_op(ops.date_sub_op)
+def date_sub_op_impl(x: ibis_types.DateValue, y: ibis_types.IntegerValue):
+    return x.cast("timestamp") - y.to_interval("us")  # type: ignore
+
+
 @scalar_op_compiler.register_unary_op(ops.FloorDtOp, pass_op=True)
 def floor_dt_op_impl(x: ibis_types.Value, op: ops.FloorDtOp):
     supported_freqs = ["Y", "Q", "M", "W", "D", "h", "min", "s", "ms", "us", "ns"]

bigframes/core/rewrite/timedeltas.py

@@ -151,6 +151,12 @@ def _rewrite_sub_op(left: _TypedExpr, right: _TypedExpr) -> _TypedExpr:
     if dtypes.is_datetime_like(left.dtype) and right.dtype is dtypes.TIMEDELTA_DTYPE:
         return _TypedExpr.create_op_expr(ops.timestamp_sub_op, left, right)
 
+    if left.dtype == dtypes.DATE_DTYPE and right.dtype == dtypes.DATE_DTYPE:
+        return _TypedExpr.create_op_expr(ops.date_diff_op, left, right)
+
+    if left.dtype == dtypes.DATE_DTYPE and right.dtype is dtypes.TIMEDELTA_DTYPE:
+        return _TypedExpr.create_op_expr(ops.date_sub_op, left, right)
+
     return _TypedExpr.create_op_expr(ops.sub_op, left, right)
 
 
@@ -163,6 +169,14 @@ def _rewrite_add_op(left: _TypedExpr, right: _TypedExpr) -> _TypedExpr:
         # always on the right.
         return _TypedExpr.create_op_expr(ops.timestamp_add_op, right, left)
 
+    if left.dtype == dtypes.DATE_DTYPE and right.dtype is dtypes.TIMEDELTA_DTYPE:
+        return _TypedExpr.create_op_expr(ops.date_add_op, left, right)
+
+    if left.dtype is dtypes.TIMEDELTA_DTYPE and right.dtype == dtypes.DATE_DTYPE:
+        # Re-arrange operands such that date is always on the left and timedelta is
+        # always on the right.
+        return _TypedExpr.create_op_expr(ops.date_add_op, right, left)
+
     return _TypedExpr.create_op_expr(ops.add_op, left, right)
 
 

bigframes/operations/__init__.py

@@ -39,6 +39,7 @@
     ne_op,
 )
 from bigframes.operations.date_ops import (
+    date_diff_op,
     day_op,
     dayofweek_op,
     month_op,
@@ -184,6 +185,8 @@
 from bigframes.operations.struct_ops import StructFieldOp, StructOp
 from bigframes.operations.time_ops import hour_op, minute_op, normalize_op, second_op
 from bigframes.operations.timedelta_ops import (
+    date_add_op,
+    date_sub_op,
     timedelta_floor_op,
     timestamp_add_op,
     timestamp_sub_op,
@@ -249,6 +252,7 @@
     "upper_op",
     "ZfillOp",
     # Date ops
+    "date_diff_op",
     "day_op",
     "month_op",
     "year_op",
@@ -260,6 +264,8 @@
     "second_op",
     "normalize_op",
     # Timedelta ops
+    "date_add_op",
+    "date_sub_op",
     "timedelta_floor_op",
     "timestamp_add_op",
     "timestamp_sub_op",

bigframes/operations/date_ops.py

@@ -12,6 +12,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import dataclasses
+import typing
+
+from bigframes import dtypes
 from bigframes.operations import base_ops
 import bigframes.operations.type as op_typing
 
@@ -39,3 +43,22 @@
     name="quarter",
     type_signature=op_typing.DATELIKE_ACCESSOR,
 )
+
+
+@dataclasses.dataclass(frozen=True)
+class DateDiffOp(base_ops.BinaryOp):
+    name: typing.ClassVar[str] = "date_diff"
+
+    def output_type(self, *input_types: dtypes.ExpressionType) -> dtypes.ExpressionType:
+        if input_types[0] is not input_types[1]:
+            raise TypeError(
+                f"two inputs have different types. left: {input_types[0]}, right: {input_types[1]}"
+            )
+
+        if input_types[0] != dtypes.DATE_DTYPE:
+            raise TypeError("expected date input")
+
+        return dtypes.TIMEDELTA_DTYPE
+
+
+date_diff_op = DateDiffOp()

bigframes/operations/numeric_ops.py

@@ -123,12 +123,18 @@ def output_type(self, *input_types):
             # String addition
             return input_types[0]
 
-        # Timestamp addition.
+        # Temporal addition.
         if dtypes.is_datetime_like(left_type) and right_type is dtypes.TIMEDELTA_DTYPE:
             return left_type
         if left_type is dtypes.TIMEDELTA_DTYPE and dtypes.is_datetime_like(right_type):
             return right_type
 
+        if left_type == dtypes.DATE_DTYPE and right_type == dtypes.TIMEDELTA_DTYPE:
+            return dtypes.DATETIME_DTYPE
+
+        if left_type == dtypes.TIMEDELTA_DTYPE and right_type == dtypes.DATE_DTYPE:
+            return dtypes.DATETIME_DTYPE
+
         if left_type is dtypes.TIMEDELTA_DTYPE and right_type is dtypes.TIMEDELTA_DTYPE:
             return dtypes.TIMEDELTA_DTYPE
 
@@ -155,9 +161,15 @@ def output_type(self, *input_types):
         if dtypes.is_datetime_like(left_type) and dtypes.is_datetime_like(right_type):
             return dtypes.TIMEDELTA_DTYPE
 
+        if left_type == dtypes.DATE_DTYPE and right_type == dtypes.DATE_DTYPE:
+            return dtypes.TIMEDELTA_DTYPE
+
         if dtypes.is_datetime_like(left_type) and right_type is dtypes.TIMEDELTA_DTYPE:
             return left_type
 
+        if left_type == dtypes.DATE_DTYPE and right_type == dtypes.TIMEDELTA_DTYPE:
+            return dtypes.DATETIME_DTYPE
+
         if left_type is dtypes.TIMEDELTA_DTYPE and right_type is dtypes.TIMEDELTA_DTYPE:
             return dtypes.TIMEDELTA_DTYPE
 

bigframes/operations/timedelta_ops.py

@@ -79,6 +79,7 @@ def output_type(self, *input_types: dtypes.ExpressionType) -> dtypes.ExpressionT
 timestamp_add_op = TimestampAddOp()
 
 
+@dataclasses.dataclass(frozen=True)
 class TimestampSubOp(base_ops.BinaryOp):
     name: typing.ClassVar[str] = "timestamp_sub"
 
@@ -96,3 +97,49 @@ def output_type(self, *input_types: dtypes.ExpressionType) -> dtypes.ExpressionT
 
 
 timestamp_sub_op = TimestampSubOp()
+
+
+@dataclasses.dataclass(frozen=True)
+class DateAddOp(base_ops.BinaryOp):
+    name: typing.ClassVar[str] = "date_add"
+
+    def output_type(self, *input_types: dtypes.ExpressionType) -> dtypes.ExpressionType:
+        # date + timedelta => timestamp without timezone
+        if (
+            input_types[0] == dtypes.DATE_DTYPE
+            and input_types[1] == dtypes.TIMEDELTA_DTYPE
+        ):
+            return dtypes.DATETIME_DTYPE
+        # timedelta + date => timestamp without timezone
+        if (
+            input_types[0] == dtypes.TIMEDELTA_DTYPE
+            and input_types[1] == dtypes.DATE_DTYPE
+        ):
+            return dtypes.DATETIME_DTYPE
+
+        raise TypeError(
+            f"unsupported types for date_add. left: {input_types[0]} right: {input_types[1]}"
+        )
+
+
+date_add_op = DateAddOp()
+
+
+@dataclasses.dataclass(frozen=True)
+class DateSubOp(base_ops.BinaryOp):
+    name: typing.ClassVar[str] = "date_sub"
+
+    def output_type(self, *input_types: dtypes.ExpressionType) -> dtypes.ExpressionType:
+        # date - timedelta => timestamp without timezone
+        if (
+            input_types[0] == dtypes.DATE_DTYPE
+            and input_types[1] == dtypes.TIMEDELTA_DTYPE
+        ):
+            return dtypes.DATETIME_DTYPE
+
+        raise TypeError(
+            f"unsupported types for date_sub. left: {input_types[0]} right: {input_types[1]}"
+        )
+
+
+date_sub_op = DateSubOp()

setup.py

@@ -52,7 +52,7 @@
     "numpy >=1.24.0",
     "pandas >=1.5.3",
     "pandas-gbq >=0.26.0",
-    "pyarrow >=10.0.1",
+    "pyarrow >=15.0.2",
     "pydata-google-auth >=1.8.2",
     "requests >=2.27.1",
     "sqlglot >=23.6.3",

testing/constraints-3.12.txt

@@ -0,0 +1 @@
+pandas==2.2.0

testing/constraints-3.9.txt

@@ -16,7 +16,7 @@ jellyfish==0.8.9
 numpy==1.24.0
 pandas==1.5.3
 pandas-gbq==0.26.0
-pyarrow==10.0.1
+pyarrow==15.0.2
 pydata-google-auth==1.8.2
 requests==2.27.1
 scikit-learn==1.2.2

tests/system/small/operations/test_dates.py

@@ -0,0 +1,61 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import datetime
+
+import pandas as pd
+import pandas.testing
+
+from bigframes import dtypes
+
+
+def test_date_diff_between_series(session):
+    pd_df = pd.DataFrame(
+        {
+            "col_1": [datetime.date(2025, 1, 2), datetime.date(2025, 2, 1)],
+            "col_2": [datetime.date(2024, 1, 2), datetime.date(2026, 1, 30)],
+        }
+    ).astype(dtypes.DATE_DTYPE)
+    bf_df = session.read_pandas(pd_df)
+
+    actual_result = (bf_df["col_1"] - bf_df["col_2"]).to_pandas()
+
+    expected_result = (pd_df["col_1"] - pd_df["col_2"]).astype(dtypes.TIMEDELTA_DTYPE)
+    pandas.testing.assert_series_equal(
+        actual_result, expected_result, check_index_type=False
+    )
+
+
+def test_date_diff_literal_sub_series(scalars_dfs):
+    bf_df, pd_df = scalars_dfs
+    literal = datetime.date(2030, 5, 20)
+
+    actual_result = (literal - bf_df["date_col"]).to_pandas()
+
+    expected_result = (literal - pd_df["date_col"]).astype(dtypes.TIMEDELTA_DTYPE)
+    pandas.testing.assert_series_equal(
+        actual_result, expected_result, check_index_type=False
+    )
+
+
+def test_date_diff_series_sub_literal(scalars_dfs):
+    bf_df, pd_df = scalars_dfs
+    literal = datetime.date(1980, 5, 20)
+
+    actual_result = (bf_df["date_col"] - literal).to_pandas()
+
+    expected_result = (pd_df["date_col"] - literal).astype(dtypes.TIMEDELTA_DTYPE)
+    pandas.testing.assert_series_equal(
+        actual_result, expected_result, check_index_type=False
+    )