diff --git a/velox/expression/tests/CastExprTest.cpp b/velox/expression/tests/CastExprTest.cpp
index e37fd5536a61b..7c35dfe8a163d 100644
--- a/velox/expression/tests/CastExprTest.cpp
+++ b/velox/expression/tests/CastExprTest.cpp
@@ -1265,10 +1265,9 @@ TEST_F(CastExprTest, truncateVsRound) {
       "tinyint", {1111111, 2, 3, 1000, -100101}, {71, 2, 3, -24, -5});
 
   setCastIntByTruncate(false);
-  EXPECT_THROW(
-      (testCast<int32_t, int8_t>(
-          "tinyint", {1111111, 2, 3, 1000, -100101}, {71, 2, 3, -24, -5})),
-      VeloxUserError);
+  testCast<int32_t, int8_t>("tinyint", {2, 3}, {2, 3});
+  testCast<int32_t, int8_t>(
+      "tinyint", {1111111, 1000, -100101}, {0, 0, 0}, true);
 }
 
 TEST_F(CastExprTest, nullInputs) {
diff --git a/velox/type/tests/CMakeLists.txt b/velox/type/tests/CMakeLists.txt
index 1106ed087ec70..4b71c38e32e61 100644
--- a/velox/type/tests/CMakeLists.txt
+++ b/velox/type/tests/CMakeLists.txt
@@ -22,7 +22,8 @@ add_executable(
   SubfieldTest.cpp
   TimestampConversionTest.cpp
   VariantTest.cpp
-  TimestampTest.cpp)
+  TimestampTest.cpp
+  ConversionsTest.cpp)
 
 add_test(velox_type_test velox_type_test)
 
diff --git a/velox/type/tests/ConversionsTest.cpp b/velox/type/tests/ConversionsTest.cpp
new file mode 100644
index 0000000000000..6708174fcfcd4
--- /dev/null
+++ b/velox/type/tests/ConversionsTest.cpp
@@ -0,0 +1,1007 @@
+/*
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * 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.
+ */
+#include "velox/type/Conversions.h"
+#include "gtest/gtest.h"
+#include "velox/common/base/VeloxException.h"
+#include "velox/common/base/tests/GTestUtils.h"
+
+using namespace facebook::velox;
+
+namespace facebook::velox::util {
+namespace {
+
+constexpr float kInf = std::numeric_limits<float>::infinity();
+constexpr float kNan = std::numeric_limits<float>::quiet_NaN();
+
+class ConversionsTest : public testing::Test {
+ protected:
+  template <typename TFrom, typename TTo>
+  static void testConversion(
+      std::vector<TFrom> input,
+      std::vector<TTo> expectedResult,
+      bool truncate = false,
+      bool legacyCast = false,
+      bool expectError = false) {
+    if (!expectError) {
+      VELOX_CHECK_EQ(input.size(), expectedResult.size());
+    }
+    const TypeKind toTypeKind = CppToType<TTo>::typeKind;
+
+    auto cast = [&](TFrom input) -> TTo {
+      if (truncate & legacyCast) {
+        return Converter<toTypeKind, void, true, true>::cast(input);
+      } else if (!truncate & legacyCast) {
+        return Converter<toTypeKind, void, false, true>::cast(input);
+      } else if (truncate & !legacyCast) {
+        return Converter<toTypeKind, void, true, false>::cast(input);
+      } else {
+        return Converter<toTypeKind, void, false, false>::cast(input);
+      }
+    };
+
+    for (auto i = 0; i < input.size(); i++) {
+      if (expectError) {
+        ASSERT_ANY_THROW(cast(input[i])) << "Converting input at " << i;
+      } else {
+        TTo actual = cast(input[i]);
+        TTo expected = expectedResult[i];
+        if constexpr (std::is_floating_point_v<TTo>) {
+          if (std::isnan(actual)) {
+            ASSERT_TRUE(std::isnan(expected))
+                << ", when actual is NaN, and converting input at " << i;
+          } else if (std::isnan(expected)) {
+            ASSERT_TRUE(std::isnan(actual))
+                << ", when expected is NaN, and converting input at " << i;
+          } else {
+            ASSERT_EQ(actual, expected) << "Converting input at " << i;
+          }
+        } else {
+          ASSERT_EQ(actual, expected) << "Converting input at " << i;
+        }
+      }
+    }
+  }
+};
+
+TEST_F(ConversionsTest, toBoolean) {
+  // From integral types.
+  {
+    // When TRUNCATE = false.
+    testConversion<int8_t, bool>(
+        {
+            1,
+            0,
+            12,
+            -1,
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = true.
+    testConversion<int8_t, bool>(
+        {
+            1,
+            0,
+            12,
+            -1,
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+        },
+        /*truncate*/ true);
+  }
+
+  // From double.
+  {
+    // When TRUNCATE = false.
+    testConversion<double, bool>(
+        {
+            1.0,
+            1.1,
+            -1.0,
+            0.0000000000001,
+        },
+        {
+            true,
+            true,
+            true,
+            true,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = true.
+    testConversion<double, bool>(
+        {
+            1.0,
+            1.1,
+            -1.0,
+            0.0000000000001,
+        },
+        {
+            true,
+            true,
+            true,
+            true,
+        },
+        /*truncate*/ true);
+  }
+
+  // From float.
+  {
+    // When TRUNCATE = false.
+    testConversion<float, bool>(
+        {
+            0.1,
+            0.0,
+            -0.1,
+            kInf,
+            kNan,
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+            true,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = true.
+    testConversion<float, bool>(
+        {
+            0.1,
+            0.0,
+            -0.1,
+            kInf,
+            kNan,
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+            false,
+        },
+        /*truncate*/ true);
+  }
+
+  // From string.
+  {
+    // When TRUNCATE = false.
+    testConversion<std::string, bool>(
+        {
+            "1",
+            "0",
+            "t",
+            "true",
+            "f",
+            "false",
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+            false,
+            false,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<std::string, bool>(
+        {
+            "1.7E308",
+            "nan",
+            "infinity",
+            "12",
+            "-1",
+            "tr",
+            "tru",
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<std::string, bool>(
+        {
+            "1",
+            "0",
+            "t",
+            "true",
+            "f",
+            "false",
+        },
+        {
+            true,
+            false,
+            true,
+            true,
+            false,
+            false,
+        },
+        /*truncate*/ true);
+
+    // When TRUNCATE = true, invalid cases.
+    testConversion<std::string, bool>(
+        {
+            "1.7E308",
+            "nan",
+            "infinity",
+            "12",
+            "-1",
+            "tr",
+            "tru",
+        },
+        {},
+        /*truncate*/ true,
+        false,
+        /*expectError*/ true);
+  }
+
+  // From timestamp.
+  {
+    // When TRUNCATE = false, invalid cases.
+    testConversion<Timestamp, bool>(
+        {Timestamp(946729316, 123)},
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+
+    // When TRUNCATE = true, invalid cases.
+    testConversion<Timestamp, bool>(
+        {Timestamp(946729316, 123)},
+        {},
+        /*truncate*/ true,
+        false,
+        /*expectError*/ true);
+  }
+}
+
+TEST_F(ConversionsTest, toIntegeralTypes) {
+  // From double.
+  {
+    // When TRUNCATE = false.
+    testConversion<double, int64_t>(
+        {
+            12345.12,
+            12345.67,
+        },
+        {
+            12345,
+            12346,
+        },
+        /*truncate*/ false);
+    testConversion<double, int32_t>(
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+        },
+        {
+            2,
+            3,
+            4,
+            100,
+            -100,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<double, int8_t>(
+        {
+            12345.67,
+            -12345.67,
+            127.8,
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<double, int64_t>(
+        {
+            12345.12,
+            12345.67,
+        },
+        {
+            12345,
+            12345,
+        },
+        /*truncate*/ true);
+    testConversion<double, int32_t>(
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+        },
+        {
+            1,
+            2,
+            3,
+            100,
+            -100,
+        },
+        /*truncate*/ true);
+    testConversion<double, int8_t>(
+        {
+            12345.67,
+            -12345.67,
+            127.8,
+        },
+        {
+            57,
+            -57,
+            127,
+        },
+        /*truncate*/ true);
+    testConversion<double, int8_t>(
+        {
+            1,
+            256,
+            257,
+            2147483646,
+            2147483647,
+            2147483648,
+            -2147483646,
+            -2147483647,
+            -2147483648,
+            -2147483649,
+        },
+        {
+            1,
+            0,
+            1,
+            -2,
+            -1,
+            -1,
+            2,
+            1,
+            0,
+            0,
+        },
+        /*truncate*/ true);
+  }
+
+  // From float.
+  {
+    // When TRUNCATE = false, invalid cases.
+    testConversion<float, int64_t>(
+        {kInf}, {}, /*truncate*/ false, false, /*expectError*/ true);
+    testConversion<float, int64_t>(
+        {kNan}, {0}, /*truncate*/ false, false, /*expectError*/ true);
+    testConversion<float, int32_t>(
+        {kNan}, {0}, /*truncate*/ false, false, /*expectError*/ true);
+    testConversion<float, int16_t>(
+        {kNan}, {0}, /*truncate*/ false, false, /*expectError*/ true);
+    testConversion<float, int8_t>(
+        {kNan}, {0}, /*truncate*/ false, false, /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<float, int64_t>(
+        {kInf}, {9223372036854775807}, /*truncate*/ true);
+    testConversion<float, int64_t>({kNan}, {0}, /*truncate*/ true);
+    testConversion<float, int32_t>({kNan}, {0}, /*truncate*/ true);
+    testConversion<float, int16_t>({kNan}, {0}, /*truncate*/ true);
+    testConversion<float, int8_t>({kNan}, {0}, /*truncate*/ true);
+  }
+
+  // From string.
+  {
+    // When TRUNCATE = false.
+    testConversion<std::string, int16_t>(
+        {
+            "1",
+            "+1",
+            "-100",
+        },
+        {
+            1,
+            1,
+            -100,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<std::string, int8_t>(
+        {
+            "1.2",
+            "1.23444",
+            ".2355",
+            "-1.8",
+            "1.",
+            "-1.",
+            "0.",
+            ".",
+            "-.",
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+    testConversion<std::string, int8_t>(
+        {"1234567"}, {}, /*truncate*/ false, false, /*expectError*/ true);
+    testConversion<std::string, int64_t>(
+        {
+            "1a",
+            "",
+            "1'234'567",
+            "1,234,567",
+            "infinity",
+            "nan",
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<std::string, int8_t>(
+        {
+            "1.2",
+            "1.23444",
+            ".2355",
+            "-1.8",
+            "1.",
+            "-1.",
+            "0.",
+            ".",
+            "-.",
+        },
+        {
+            1,
+            1,
+            0,
+            -1,
+            1,
+            -1,
+            0,
+            0,
+            0,
+        },
+        /*truncate*/ true);
+
+    // When TRUNCATE = true, invalid cases.
+    testConversion<std::string, int8_t>(
+        {"1234567", "+1"}, {}, /*truncate*/ true, false, /*expectError*/ true);
+    testConversion<std::string, int64_t>(
+        {
+            "1a",
+            "",
+            "1'234'567",
+            "1,234,567",
+            "infinity",
+            "nan",
+        },
+        {},
+        /*truncate*/ true,
+        false,
+        /*expectError*/ true);
+  }
+
+  // From integral types.
+  {
+    // When TRUNCATE = false.
+    testConversion<int32_t, int8_t>(
+        {
+            2,
+            3,
+        },
+        {
+            2,
+            3,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<int32_t, int8_t>(
+        {
+            1234567,
+            -1234567,
+            1111111,
+            1000,
+            -100101,
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<int32_t, int8_t>(
+        {
+            1234567,
+            -1234567,
+            1111111,
+            2,
+            3,
+            1000,
+            -100101,
+        },
+        {
+            -121,
+            121,
+            71,
+            2,
+            3,
+            -24,
+            -5,
+        },
+        /*truncate*/ true);
+  }
+
+  // From boolean
+  {
+    testConversion<bool, int8_t>(
+        {
+            true,
+            false,
+        },
+        {
+            1,
+            0,
+        });
+  }
+}
+
+TEST_F(ConversionsTest, toString) {
+  // From integral types.
+  {
+    testConversion<int32_t, std::string>(
+        {
+            1,
+            2,
+            3,
+            100,
+            -100,
+        },
+        {
+            "1",
+            "2",
+            "3",
+            "100",
+            "-100",
+        });
+  }
+
+  // From double.
+  {
+    // When LEGACY_CAST = false.
+    testConversion<double, std::string>(
+        {
+            12345678901234567000.0,
+            123456789.01234567,
+            10'000'000.0,
+            12345.0,
+            0.001,
+            0.00012,
+            0.0,
+            -0.0,
+            -0.00012,
+            -0.001,
+            -12345.0,
+            -10'000'000.0,
+            -123456789.01234567,
+            -12345678901234567000.0,
+            std::numeric_limits<double>::infinity(),
+            -std::numeric_limits<double>::infinity(),
+            std::numeric_limits<double>::quiet_NaN(),
+            -std::numeric_limits<double>::quiet_NaN(),
+        },
+        {
+            "1.2345678901234567E19",
+            "1.2345678901234567E8",
+            "1.0E7",
+            "12345.0",
+            "0.001",
+            "1.2E-4",
+            "0.0",
+            "-0.0",
+            "-1.2E-4",
+            "-0.001",
+            "-12345.0",
+            "-1.0E7",
+            "-1.2345678901234567E8",
+            "-1.2345678901234567E19",
+            "Infinity",
+            "-Infinity",
+            "NaN",
+            "NaN",
+        },
+        false,
+        /*legacyCast*/ false);
+
+    // When LEGACY_CAST = true.
+    testConversion<double, std::string>(
+        {
+            12345678901234567000.0,
+            123456789.01234567,
+            10'000'000.0,
+            12345.0,
+            0.001,
+            0.00012,
+            0.0,
+            -0.0,
+            -0.00012,
+            -0.001,
+            -12345.0,
+            -10'000'000.0,
+            -123456789.01234567,
+            -12345678901234567000.0,
+            std::numeric_limits<double>::infinity(),
+            -std::numeric_limits<double>::infinity(),
+            std::numeric_limits<double>::quiet_NaN(),
+            -std::numeric_limits<double>::quiet_NaN(),
+        },
+        {
+            "12345678901234567000.0",
+            "123456789.01234567",
+            "10000000.0",
+            "12345.0",
+            "0.001",
+            "0.00012",
+            "0.0",
+            "-0.0",
+            "-0.00012",
+            "-0.001",
+            "-12345.0",
+            "-10000000.0",
+            "-123456789.01234567",
+            "-12345678901234567000.0",
+            "Infinity",
+            "-Infinity",
+            "NaN",
+            "NaN",
+        },
+        false,
+        /*legacyCast*/ true);
+  }
+
+  // From float.
+  {
+    // When LEGACY_CAST = false.
+    testConversion<float, std::string>(
+        {
+            12345678000000000000.0,
+            123456780.0,
+            10'000'000.0,
+            12345.0,
+            0.001,
+            0.00012,
+            0.0,
+            -0.0,
+            -0.00012,
+            -0.001,
+            -12345.0,
+            -10'000'000.0,
+            -123456780.0,
+            -12345678000000000000.0,
+            std::numeric_limits<float>::infinity(),
+            -std::numeric_limits<float>::infinity(),
+            std::numeric_limits<float>::quiet_NaN(),
+            -std::numeric_limits<float>::quiet_NaN(),
+        },
+        {
+            "1.2345678E19",
+            "1.2345678E8",
+            "1.0E7",
+            "12345.0",
+            "0.001",
+            "1.2E-4",
+            "0.0",
+            "-0.0",
+            "-1.2E-4",
+            "-0.001",
+            "-12345.0",
+            "-1.0E7",
+            "-1.2345678E8",
+            "-1.2345678E19",
+            "Infinity",
+            "-Infinity",
+            "NaN",
+            "NaN",
+        },
+        false,
+        /*legacyCast*/ false);
+
+    // When LEGACY_CAST = true.
+    testConversion<float, std::string>(
+        {
+            12345678000000000000.0,
+            123456780.0,
+            10'000'000.0,
+            12345.0,
+            0.001,
+            0.00012,
+            0.0,
+            -0.0,
+            -0.00012,
+            -0.001,
+            -12345.0,
+            -10'000'000.0,
+            -123456780.0,
+            -12345678000000000000.0,
+            std::numeric_limits<float>::infinity(),
+            -std::numeric_limits<float>::infinity(),
+            std::numeric_limits<float>::quiet_NaN(),
+            -std::numeric_limits<float>::quiet_NaN(),
+        },
+        {
+            "12345678295994466000.0",
+            "123456784.0",
+            "10000000.0",
+            "12345.0",
+            "0.0010000000474974513",
+            "0.00011999999696854502",
+            "0.0",
+            "-0.0",
+            "-0.00011999999696854502",
+            "-0.0010000000474974513",
+            "-12345.0",
+            "-10000000.0",
+            "-123456784.0",
+            "-12345678295994466000.0",
+            "Infinity",
+            "-Infinity",
+            "NaN",
+            "NaN",
+        },
+        false,
+        /*legacyCast*/ true);
+  }
+
+  // From Timestamp.
+  {
+    // When LEGACY_CAST = false.
+    testConversion<Timestamp, std::string>(
+        {
+            Timestamp(-946684800, 0),
+            Timestamp(-7266, 0),
+            Timestamp(0, 0),
+            Timestamp(946684800, 0),
+            Timestamp(9466848000, 0),
+            Timestamp(94668480000, 0),
+            Timestamp(946729316, 0),
+            Timestamp(946729316, 123),
+            Timestamp(946729316, 129900000),
+            Timestamp(7266, 0),
+            Timestamp(-50049331200, 0),
+            Timestamp(253405036800, 0),
+            Timestamp(-62480037600, 0),
+        },
+        {
+            "1940-01-02 00:00:00.000",
+            "1969-12-31 21:58:54.000",
+            "1970-01-01 00:00:00.000",
+            "2000-01-01 00:00:00.000",
+            "2269-12-29 00:00:00.000",
+            "4969-12-04 00:00:00.000",
+            "2000-01-01 12:21:56.000",
+            "2000-01-01 12:21:56.000",
+            "2000-01-01 12:21:56.129",
+            "1970-01-01 02:01:06.000",
+            "0384-01-01 08:00:00.000",
+            "10000-02-01 16:00:00.000",
+            "-0010-02-01 10:00:00.000",
+        },
+        false,
+        /*legacyCast*/ false);
+
+    // When LEGACY_CAST = true.
+    testConversion<Timestamp, std::string>(
+        {
+            Timestamp(946729316, 123),
+            Timestamp(-50049331200, 0),
+            Timestamp(253405036800, 0),
+            Timestamp(-62480037600, 0),
+        },
+        {
+            "2000-01-01T12:21:56.000",
+            "384-01-01T08:00:00.000",
+            "10000-02-01T16:00:00.000",
+            "-10-02-01T10:00:00.000",
+        },
+        false,
+        /*legacyCast*/ true);
+  }
+}
+
+TEST_F(ConversionsTest, toRealAndDouble) {
+  // From integral types.
+  {
+    testConversion<int8_t, float>({1}, {1.0}, /*truncate*/ false);
+    testConversion<int32_t, double>(
+        {
+            1,
+            2,
+            3,
+            100,
+            -100,
+        },
+        {
+            1.0,
+            2.0,
+            3.0,
+            100.0,
+            -100.0,
+        });
+  }
+
+  // From double.
+  {
+    // When TRUNCATE = false.
+    testConversion<double, float>(
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+            1.0,
+            -2.0,
+        },
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+            1.0,
+            -2.0,
+        },
+        /*truncate*/ false);
+    testConversion<double, double>(
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+            1.0,
+            -2.0,
+        },
+        {
+            1.888,
+            2.5,
+            3.6,
+            100.44,
+            -100.101,
+            1.0,
+            -2.0,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<double, float>(
+        {1.7E308}, {}, /*truncate*/ false, false, /*expectError*/ true);
+
+    // When TRUNCATE = true.
+    testConversion<double, float>({1.7E308}, {kInf}, /*truncate*/ true);
+  }
+
+  // From string.
+  {
+    // When TRUNCATE = false.
+    testConversion<std::string, float>(
+        {
+            "1.7E308",
+            "1.",
+            "1",
+            "infinity",
+            "-infinity",
+            "InfiNiTy",
+            "-InfiNiTy",
+            "nan",
+            "nAn",
+        },
+        {
+            kInf,
+            1.0,
+            1.0,
+            kInf,
+            -kInf,
+            kInf,
+            -kInf,
+            kNan,
+            kNan,
+        },
+        /*truncate*/ false);
+
+    // When TRUNCATE = false, invalid cases.
+    testConversion<std::string, float>(
+        {
+            "1.2a",
+            "1.2.3",
+        },
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+  }
+
+  // From Timestamp.
+  {
+    // Invalid cases.
+    testConversion<Timestamp, float>(
+        {Timestamp(946729316, 123)},
+        {},
+        /*truncate*/ false,
+        false,
+        /*expectError*/ true);
+  }
+}
+
+TEST_F(ConversionsTest, toTimestamp) {
+  // From string.
+  {
+    testConversion<std::string, Timestamp>(
+        {
+            "1970-01-01",
+            "2000-01-01",
+            "1970-01-01 00:00:00",
+            "2000-01-01 12:21:56",
+            "1970-01-01 00:00:00-02:00",
+        },
+        {
+            Timestamp(0, 0),
+            Timestamp(946684800, 0),
+            Timestamp(0, 0),
+            Timestamp(946729316, 0),
+            Timestamp(7200, 0),
+        });
+
+    // Invalid case.
+    testConversion<std::string, Timestamp>(
+        {"2012-Oct-01"}, {}, false, false, /*expectError*/ true);
+  }
+
+  // From integral types, invalid cases.
+  {
+    testConversion<int8_t, Timestamp>(
+        {123}, {}, false, false, /*expectError*/ true);
+    testConversion<int16_t, Timestamp>(
+        {12345}, {}, false, false, /*expectError*/ true);
+    testConversion<int32_t, Timestamp>(
+        {123456}, {}, false, false, /*expectError*/ true);
+    testConversion<int64_t, Timestamp>(
+        {123456}, {}, false, false, /*expectError*/ true);
+  }
+
+  // From floating-point types, invalid cases.
+  {
+    testConversion<float, Timestamp>(
+        {123456.78}, {}, false, false, /*expectError*/ true);
+    testConversion<double, Timestamp>(
+        {123456.78}, {}, false, false, /*expectError*/ true);
+  }
+}
+} // namespace
+} // namespace facebook::velox::util
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