diff --git a/spark/src/main/scala/org/apache/comet/serde/datetime.scala b/spark/src/main/scala/org/apache/comet/serde/datetime.scala
index d36b6a3b40..f093b6a74c 100644
--- a/spark/src/main/scala/org/apache/comet/serde/datetime.scala
+++ b/spark/src/main/scala/org/apache/comet/serde/datetime.scala
@@ -21,7 +21,7 @@ package org.apache.comet.serde
 
 import java.util.Locale
 
-import org.apache.spark.sql.catalyst.expressions.{Attribute, DateAdd, DateDiff, DateFormatClass, DateSub, DayOfMonth, DayOfWeek, DayOfYear, GetDateField, Hour, LastDay, Literal, MakeDate, Minute, Month, NextDay, Quarter, Second, TruncDate, TruncTimestamp, UnixDate, UnixTimestamp, WeekDay, WeekOfYear, Year}
+import org.apache.spark.sql.catalyst.expressions.{Attribute, DateAdd, DateDiff, DateFormatClass, DateSub, DayOfMonth, DayOfWeek, DayOfYear, Expression, GetDateField, Hour, LastDay, Literal, MakeDate, Minute, Month, NextDay, Quarter, Second, TruncDate, TruncTimestamp, UnixDate, UnixTimestamp, WeekDay, WeekOfYear, Year}
 import org.apache.spark.sql.types.{DateType, IntegerType, StringType, TimestampType}
 import org.apache.spark.unsafe.types.UTF8String
 
@@ -541,3 +541,36 @@ object CometDateFormat extends CometExpressionSerde[DateFormatClass] {
     }
   }
 }
+
+trait CommonDateTimeExprs {
+
+  def secondsOfTimeToProto(
+      expr: Expression,
+      inputs: Seq[Attribute],
+      binding: Boolean): Option[Expr] = {
+    val childOpt = expr.children.headOption.orElse {
+      withInfo(expr, "SecondsOfTime has no child expression")
+      None
+    }
+
+    childOpt.flatMap { child =>
+      exprToProtoInternal(child, inputs, binding)
+        .map { childExpr =>
+          val builder = ExprOuterClass.Second.newBuilder()
+          builder.setChild(childExpr)
+
+          // SecondsOfTime does not carry a timeZoneId; assume UTC.
+          builder.setTimezone("UTC")
+
+          ExprOuterClass.Expr
+            .newBuilder()
+            .setSecond(builder)
+            .build()
+        }
+        .orElse {
+          withInfo(expr, child)
+          None
+        }
+    }
+  }
+}
diff --git a/spark/src/main/spark-3.4/org/apache/comet/shims/CometExprShim.scala b/spark/src/main/spark-3.4/org/apache/comet/shims/CometExprShim.scala
index 600931c346..3d36d0ace0 100644
--- a/spark/src/main/spark-3.4/org/apache/comet/shims/CometExprShim.scala
+++ b/spark/src/main/spark-3.4/org/apache/comet/shims/CometExprShim.scala
@@ -22,13 +22,13 @@ package org.apache.comet.shims
 import org.apache.spark.sql.catalyst.expressions._
 
 import org.apache.comet.expressions.CometEvalMode
-import org.apache.comet.serde.CommonStringExprs
+import org.apache.comet.serde.{CommonDateTimeExprs, CommonStringExprs}
 import org.apache.comet.serde.ExprOuterClass.{BinaryOutputStyle, Expr}
 
 /**
  * `CometExprShim` acts as a shim for parsing expressions from different Spark versions.
  */
-trait CometExprShim extends CommonStringExprs {
+trait CometExprShim extends CommonStringExprs with CommonDateTimeExprs {
   protected def evalMode(c: Cast): CometEvalMode.Value =
     CometEvalModeUtil.fromSparkEvalMode(c.evalMode)
 
@@ -43,6 +43,10 @@ trait CometExprShim extends CommonStringExprs {
         // Right child is the encoding expression.
         stringDecode(expr, s.charset, s.bin, inputs, binding)
 
+      case _: UnaryExpression if expr.prettyName == "seconds_of_time" =>
+        // SecondsOfTime may not exist in all Spark versions, so we match by prettyName
+        secondsOfTimeToProto(expr, inputs, binding)
+
       case _ => None
     }
   }
diff --git a/spark/src/main/spark-3.5/org/apache/comet/shims/CometExprShim.scala b/spark/src/main/spark-3.5/org/apache/comet/shims/CometExprShim.scala
index 8e9cb1c07b..b61a5a4b18 100644
--- a/spark/src/main/spark-3.5/org/apache/comet/shims/CometExprShim.scala
+++ b/spark/src/main/spark-3.5/org/apache/comet/shims/CometExprShim.scala
@@ -24,14 +24,14 @@ import org.apache.spark.sql.types.DataTypes
 
 import org.apache.comet.CometSparkSessionExtensions.withInfo
 import org.apache.comet.expressions.{CometCast, CometEvalMode}
-import org.apache.comet.serde.{CommonStringExprs, Compatible, ExprOuterClass, Incompatible}
+import org.apache.comet.serde.{CommonDateTimeExprs, CommonStringExprs, Compatible, ExprOuterClass, Incompatible}
 import org.apache.comet.serde.ExprOuterClass.{BinaryOutputStyle, Expr}
 import org.apache.comet.serde.QueryPlanSerde.exprToProtoInternal
 
 /**
  * `CometExprShim` acts as a shim for parsing expressions from different Spark versions.
  */
-trait CometExprShim extends CommonStringExprs {
+trait CometExprShim extends CommonStringExprs with CommonDateTimeExprs {
   protected def evalMode(c: Cast): CometEvalMode.Value =
     CometEvalModeUtil.fromSparkEvalMode(c.evalMode)
 
@@ -91,6 +91,10 @@ trait CometExprShim extends CommonStringExprs {
 //        val optExpr = scalarFunctionExprToProto("width_bucket", childExprs: _*)
 //        optExprWithInfo(optExpr, wb, wb.children: _*)
 
+      case _: UnaryExpression if expr.prettyName == "seconds_of_time" =>
+        // SecondsOfTime may not exist in all Spark versions, so we match by prettyName
+        secondsOfTimeToProto(expr, inputs, binding)
+
       case _ => None
     }
   }
diff --git a/spark/src/main/spark-4.0/org/apache/comet/shims/CometExprShim.scala b/spark/src/main/spark-4.0/org/apache/comet/shims/CometExprShim.scala
index 2c5cebd166..de8eef389a 100644
--- a/spark/src/main/spark-4.0/org/apache/comet/shims/CometExprShim.scala
+++ b/spark/src/main/spark-4.0/org/apache/comet/shims/CometExprShim.scala
@@ -27,14 +27,14 @@ import org.apache.spark.sql.types.{BinaryType, BooleanType, DataTypes, StringTyp
 
 import org.apache.comet.CometSparkSessionExtensions.withInfo
 import org.apache.comet.expressions.{CometCast, CometEvalMode}
-import org.apache.comet.serde.{CommonStringExprs, Compatible, ExprOuterClass, Incompatible}
+import org.apache.comet.serde.{CommonDateTimeExprs, CommonStringExprs, Compatible, ExprOuterClass, Incompatible}
 import org.apache.comet.serde.ExprOuterClass.{BinaryOutputStyle, Expr}
 import org.apache.comet.serde.QueryPlanSerde.exprToProtoInternal
 
 /**
  * `CometExprShim` acts as a shim for parsing expressions from different Spark versions.
  */
-trait CometExprShim extends CommonStringExprs {
+trait CometExprShim extends CommonStringExprs with CommonDateTimeExprs {
   protected def evalMode(c: Cast): CometEvalMode.Value =
     CometEvalModeUtil.fromSparkEvalMode(c.evalMode)
 
@@ -113,6 +113,10 @@ trait CometExprShim extends CommonStringExprs {
 //        val optExpr = scalarFunctionExprToProto("width_bucket", childExprs: _*)
 //        optExprWithInfo(optExpr, wb, wb.children: _*)
 
+      case _: UnaryExpression if expr.prettyName == "seconds_of_time" =>
+        // SecondsOfTime may not exist in all Spark versions, so we match by prettyName
+        secondsOfTimeToProto(expr, inputs, binding)
+
       case _ => None
     }
   }
diff --git a/spark/src/test/scala/org/apache/comet/CometExpressionSuite.scala b/spark/src/test/scala/org/apache/comet/CometExpressionSuite.scala
index f0f022868f..fb7b096b84 100644
--- a/spark/src/test/scala/org/apache/comet/CometExpressionSuite.scala
+++ b/spark/src/test/scala/org/apache/comet/CometExpressionSuite.scala
@@ -572,6 +572,23 @@ class CometExpressionSuite extends CometTestBase with AdaptiveSparkPlanHelper {
     }
   }
 
+  test("seconds_of_time expression") {
+    // This test verifies that seconds() function works correctly with timestamp columns.
+    // If Spark generates SecondOfTime expression (a RuntimeReplaceable expression),
+    // it will be handled by the version-specific shim and converted to Second proto.
+    Seq(true, false).foreach { dictionaryEnabled =>
+      withTempDir { dir =>
+        val path = new Path(dir.toURI.toString, "part-r-0.parquet")
+        makeRawTimeParquetFile(path, dictionaryEnabled = dictionaryEnabled, 10000)
+        readParquetFile(path.toString) { df =>
+          val query = df.select(expr("second(_1)"))
+
+          checkSparkAnswerAndOperator(query)
+        }
+      }
+    }
+  }
+
   test("hour on int96 timestamp column") {
     import testImplicits._