diff --git a/src/java/com/samskivert/jdbc/depot/BindVisitor.java b/src/java/com/samskivert/jdbc/depot/BindVisitor.java
index 1274c07..eab550a 100644
--- a/src/java/com/samskivert/jdbc/depot/BindVisitor.java
+++ b/src/java/com/samskivert/jdbc/depot/BindVisitor.java
@@ -38,6 +38,7 @@ import com.samskivert.jdbc.depot.clause.SelectClause;
 import com.samskivert.jdbc.depot.clause.UpdateClause;
 import com.samskivert.jdbc.depot.clause.Where;
 import com.samskivert.jdbc.depot.expression.ColumnExp;
+import com.samskivert.jdbc.depot.expression.EpochSeconds;
 import com.samskivert.jdbc.depot.expression.ExpressionVisitor;
 import com.samskivert.jdbc.depot.expression.FunctionExp;
 import com.samskivert.jdbc.depot.expression.LiteralExp;
@@ -105,6 +106,12 @@ public class BindVisitor implements ExpressionVisitor
         visit(functionExp.getArguments());
     }
 
+    public void visit (EpochSeconds epochSeconds)
+        throws Exception
+    {
+        epochSeconds.getArgument().accept(this);
+    }
+
     public void visit (MultiOperator multiOperator)
         throws Exception
     {
diff --git a/src/java/com/samskivert/jdbc/depot/MySQLBuilder.java b/src/java/com/samskivert/jdbc/depot/MySQLBuilder.java
index 59887b8..89abd5e 100644
--- a/src/java/com/samskivert/jdbc/depot/MySQLBuilder.java
+++ b/src/java/com/samskivert/jdbc/depot/MySQLBuilder.java
@@ -47,6 +47,7 @@ import com.samskivert.jdbc.depot.FieldMarshaller.ShortMarshaller;
 import com.samskivert.jdbc.depot.annotation.FullTextIndex;
 import com.samskivert.jdbc.depot.clause.DeleteClause;
 import com.samskivert.jdbc.depot.expression.ColumnExp;
+import com.samskivert.jdbc.depot.expression.EpochSeconds;
 import com.samskivert.jdbc.depot.operator.Conditionals.FullTextMatch;
 
 public class MySQLBuilder
@@ -89,6 +90,14 @@ public class MySQLBuilder
             }
         }
 
+        public void visit (EpochSeconds epochSeconds)
+            throws Exception
+        {
+            _builder.append("unix_timestamp(");
+            epochSeconds.getArgument().accept(this);
+            _builder.append(")");
+        }
+
         protected MSBuildVisitor (DepotTypes types)
         {
             super(types);
diff --git a/src/java/com/samskivert/jdbc/depot/PostgreSQLBuilder.java b/src/java/com/samskivert/jdbc/depot/PostgreSQLBuilder.java
index c14218f..1c20476 100644
--- a/src/java/com/samskivert/jdbc/depot/PostgreSQLBuilder.java
+++ b/src/java/com/samskivert/jdbc/depot/PostgreSQLBuilder.java
@@ -46,6 +46,7 @@ import com.samskivert.jdbc.depot.FieldMarshaller.LongMarshaller;
 import com.samskivert.jdbc.depot.FieldMarshaller.ObjectMarshaller;
 import com.samskivert.jdbc.depot.FieldMarshaller.ShortMarshaller;
 import com.samskivert.jdbc.depot.annotation.FullTextIndex;
+import com.samskivert.jdbc.depot.expression.EpochSeconds;
 import com.samskivert.jdbc.depot.operator.Conditionals.FullTextMatch;
 import com.samskivert.util.ArrayUtil;
 import com.samskivert.util.StringUtil;
@@ -65,6 +66,14 @@ public class PostgreSQLBuilder
             _builder.append(" @@ TO_TSQUERY('default', ?)");
         }
 
+        public void visit (EpochSeconds epochSeconds)
+            throws Exception
+        {
+            _builder.append("date_part('epoch', ");
+            epochSeconds.getArgument().accept(this);
+            _builder.append(")");
+        }
+
         protected PGBuildVisitor (DepotTypes types)
         {
             super(types);
diff --git a/src/java/com/samskivert/jdbc/depot/expression/EpochSeconds.java b/src/java/com/samskivert/jdbc/depot/expression/EpochSeconds.java
new file mode 100644
index 0000000..e9d164b
--- /dev/null
+++ b/src/java/com/samskivert/jdbc/depot/expression/EpochSeconds.java
@@ -0,0 +1,60 @@
+//
+// $Id$
+//
+// samskivert library - useful routines for java programs
+// Copyright (C) 2006-2007 Michael Bayne, Pär Winzell
+//
+// This library is free software; you can redistribute it and/or modify it
+// under the terms of the GNU Lesser General Public License as published
+// by the Free Software Foundation; either version 2.1 of the License, or
+// (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+
+package com.samskivert.jdbc.depot.expression;
+
+import java.util.Collection;
+
+import com.samskivert.jdbc.depot.PersistentRecord;
+
+/**
+ * An expression for extracting the seconds since the epoch from a date expression.
+ */
+public class EpochSeconds implements SQLExpression
+{
+    /**
+     * Create a new EpochSeconds with the given argument.
+     */
+    public EpochSeconds (SQLExpression arg)
+    {
+        _arg = arg;
+    }
+
+    // from SQLExpression
+    public void accept (ExpressionVisitor builder)
+        throws Exception
+    {
+        builder.visit(this);
+    }
+
+    // from SQLExpression
+    public void addClasses (Collection<Class<? extends PersistentRecord>> classSet)
+    {
+        _arg.addClasses(classSet);
+    }
+
+    public SQLExpression getArgument ()
+    {
+        return _arg;
+    }
+
+    /** The argument. */
+    protected SQLExpression _arg;
+}
diff --git a/src/java/com/samskivert/jdbc/depot/expression/ExpressionVisitor.java b/src/java/com/samskivert/jdbc/depot/expression/ExpressionVisitor.java
index 3245ea0..9fa59fb 100644
--- a/src/java/com/samskivert/jdbc/depot/expression/ExpressionVisitor.java
+++ b/src/java/com/samskivert/jdbc/depot/expression/ExpressionVisitor.java
@@ -61,6 +61,8 @@ public interface ExpressionVisitor
         throws Exception;
     public void visit (FunctionExp functionExp)
         throws Exception;
+    public void visit (EpochSeconds epochSeconds)
+        throws Exception;
     public void visit (FromOverride fromOverride)
         throws Exception;
     public void visit (MultiOperator multiOperator)