diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/Grammar.java b/querydsl-core/src/main/java/com/mysema/query/grammar/Grammar.java
index b882f1de1..754c75a7c 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/Grammar.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/Grammar.java
@@ -96,11 +96,11 @@ public class Grammar {
     }
     
     public static Expr<Character> charAt(Expr<String> left, Expr<Integer> right) {
-        return createComparable(Ops.CHAR_AT, left, right);
+        return createComparable(Character.class, Ops.CHAR_AT, left, right);
     }
         
     public static Expr<Character> charAt(Expr<String> left, int right) {
-        return createComparable(Ops.CHAR_AT, left, createConstant(right));
+        return createComparable(Character.class, Ops.CHAR_AT, left, createConstant(right));
     }
     
     public static EString concat(Expr<String> left, Expr<String> right) {
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/Ops.java b/querydsl-core/src/main/java/com/mysema/query/grammar/Ops.java
index 5c84038f0..11633ba27 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/Ops.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/Ops.java
@@ -78,16 +78,29 @@ public interface Ops {
     Op<Boolean> ENDSWITH = new Op<Boolean>();
     Op<Boolean> CONTAINS = new Op<Boolean>();
     
-
-    /**
-     * The Interface OpNumberAgg.
-     */
     public interface OpNumberAgg{
         Op<Number> AVG = new Op<Number>();
         Op<Number> MAX = new Op<Number>();
         Op<Number> MIN = new Op<Number>();   
     }
     
+    public interface OpDateTime{
+        Op<java.util.Date> CURRENT_DATE = new Op<java.util.Date>();
+        Op<java.util.Date> CURRENT_TIME = new Op<java.util.Date>();
+        Op<java.util.Date> CURRENT_TIMESTAMP = new Op<java.util.Date>();
+        Op<Integer> DAY = new Op<Integer>();
+        Op<Integer> HOUR = new Op<Integer>();        
+        Op<Integer> MINUTE = new Op<Integer>();
+        Op<Integer> MONTH = new Op<Integer>();
+        Op<Integer> SECOND = new Op<Integer>();        
+        Op<java.util.Date> SYSDATE = new Op<java.util.Date>();
+        Op<Integer> YEAR = new Op<Integer>();
+        Op<Integer> WEEK = new Op<Integer>();
+        Op<Integer> DAY_OF_WEEK = new Op<Integer>();
+        Op<Integer> DAY_OF_MONTH = new Op<Integer>();
+        Op<Integer> DAY_OF_YEAR =new Op<Integer>();
+    }
+    
     public interface OpMath{
         Op<Number> ABS = new Op<Number>();
         Op<Number> ACOS = new Op<Number>();
@@ -107,7 +120,13 @@ public interface Ops {
         Op<Number> LOG10 = new Op<Number>();
         Op<Number> LOG = new Op<Number>();
         Op<Number> FLOOR = new Op<Number>();
-        Op<Number> EXP = new Op<Number>();
-        
+        Op<Number> EXP = new Op<Number>();        
+    }
+    
+    public interface OpString{
+        Op<Number> LENGTH = new Op<Number>();
+        Op<String> LTRIM = new Op<String>();
+        Op<String> RTRIM = new Op<String>();
+        Op<String> SPACE = new Op<String>();
     }
 }
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/QDateTime.java b/querydsl-core/src/main/java/com/mysema/query/grammar/QDateTime.java
new file mode 100644
index 000000000..c77aa62d8
--- /dev/null
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/QDateTime.java
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2008 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
+package com.mysema.query.grammar;
+
+import java.sql.Time;
+import java.util.Date;
+
+import com.mysema.query.grammar.types.Expr;
+import com.mysema.query.grammar.types.Factory;
+import com.mysema.query.grammar.types.Expr.EComparable;
+import com.mysema.query.grammar.types.Expr.ENumber;
+
+/**
+ * QDateTime provides
+ *
+ * @author tiwe
+ * @version $Id$
+ */
+public class QDateTime extends Factory{
+
+    public static EComparable<Date> currentDate() {
+        return createComparable(Date.class, Ops.OpDateTime.CURRENT_DATE);
+    }
+
+    public static EComparable<Date> currentTime() {
+        return createComparable(Date.class, Ops.OpDateTime.CURRENT_DATE);
+        
+    }
+
+    public static ENumber<Integer> dayOfMonth(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.DAY_OF_MONTH, d);
+        
+    }
+
+    public static ENumber<Integer> dayOfWeek(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.DAY_OF_WEEK, d);
+        
+    }
+
+    public static ENumber<Integer> dayOfYear(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.DAY_OF_YEAR, d);
+        
+    }
+
+    public static ENumber<Integer> hour(Expr<Time> t) {
+        return createNumber(Integer.class, Ops.OpDateTime.HOUR, t);
+        
+    }
+
+    public static ENumber<Integer> minute(Expr<Time> t) {
+        return createNumber(Integer.class, Ops.OpDateTime.MINUTE, t);
+        
+    }
+
+    public static ENumber<Integer> year(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.YEAR, d);        
+    }
+
+    public static ENumber<Integer> week(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.WEEK, d);
+        
+    }
+
+    public static ENumber<Integer> second(Expr<Time> t) {
+        return createNumber(Integer.class, Ops.OpDateTime.SECOND, t);        
+    }
+
+    public static EComparable<Date> now() {
+        return createComparable(Date.class, Ops.OpDateTime.CURRENT_TIME);
+        
+    }
+
+    public static ENumber<Integer> month(Expr<Date> d) {
+        return createNumber(Integer.class, Ops.OpDateTime.MONTH, d);
+        
+    }
+
+}
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/QMath.java b/querydsl-core/src/main/java/com/mysema/query/grammar/QMath.java
index 6a398f723..c6ba3c8d8 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/QMath.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/QMath.java
@@ -1,11 +1,14 @@
+/*
+ * Copyright (c) 2008 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
 package com.mysema.query.grammar;
 
-import static com.mysema.query.grammar.types.Factory.createConstant;
-import static com.mysema.query.grammar.types.Factory.createNumber;
-
 import com.mysema.query.grammar.Ops.OpMath;
 import com.mysema.query.grammar.Ops.OpNumberAgg;
 import com.mysema.query.grammar.types.Expr;
+import com.mysema.query.grammar.types.Factory;
 import com.mysema.query.grammar.types.Expr.ENumber;
 
 /**
@@ -14,7 +17,7 @@ import com.mysema.query.grammar.types.Expr.ENumber;
  * @author tiwe
  * @version $Id$
  */
-public class QMath {
+public class QMath extends Factory{
         
     public static <A extends Number & Comparable<A>> ENumber<A> mult(Expr<A> left, A right) {
         return createNumber(left.getType(), Ops.MULT, left, createConstant(right));
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/QString.java b/querydsl-core/src/main/java/com/mysema/query/grammar/QString.java
new file mode 100644
index 000000000..19c1ce5c6
--- /dev/null
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/QString.java
@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2008 Mysema Ltd.
+ * All rights reserved.
+ * 
+ */
+package com.mysema.query.grammar;
+
+import com.mysema.query.grammar.types.Expr;
+import com.mysema.query.grammar.types.Factory;
+import com.mysema.query.grammar.types.Expr.ENumber;
+import com.mysema.query.grammar.types.Expr.EString;
+
+/**
+ * QString provides
+ *
+ * @author tiwe
+ * @version $Id$
+ */
+public class QString extends Factory{
+
+    public static ENumber<Integer> length(Expr<String> s) {
+        return createNumber(Integer.class, Ops.OpString.LENGTH, s);        
+    }
+
+    public static EString ltrim(Expr<String> s) {
+        return createString(Ops.OpString.LTRIM, s);
+    }
+
+    public static EString rtrim(Expr<String> s) {
+        return createString(Ops.OpString.RTRIM, s);
+    }
+
+    public static EString space(int i) {
+        return createString(Ops.OpString.SPACE, createConstant(i));        
+    }
+
+
+}
diff --git a/querydsl-core/src/main/java/com/mysema/query/grammar/types/Factory.java b/querydsl-core/src/main/java/com/mysema/query/grammar/types/Factory.java
index e39172bce..db79bcb43 100644
--- a/querydsl-core/src/main/java/com/mysema/query/grammar/types/Factory.java
+++ b/querydsl-core/src/main/java/com/mysema/query/grammar/types/Factory.java
@@ -25,10 +25,10 @@ public class Factory {
         return new Operation.OBoolean(operator, args);
     }
     
-    public static final <OpType, RT extends Comparable<RT>> Expr.EComparable<RT> createComparable(Op<OpType> operator, Expr<?>... args) {
+    public static final <OpType, RT extends Comparable<RT>> Expr.EComparable<RT> createComparable(Class<RT> type, Op<OpType> operator, Expr<?>... args) {
         checkArg("operator",operator);
         checkArg("args",args);
-        return new Operation.OComparable<OpType,RT>(operator, args);
+        return new Operation.OComparable<OpType,RT>(type, operator, args);
     }
     
     @SuppressWarnings("unchecked")
diff --git a/querydsl-core/src/main/java/com/mysema/query/serialization/OperationPatterns.java b/querydsl-core/src/main/java/com/mysema/query/serialization/OperationPatterns.java
index 46472a6f1..e73a33875 100644
--- a/querydsl-core/src/main/java/com/mysema/query/serialization/OperationPatterns.java
+++ b/querydsl-core/src/main/java/com/mysema/query/serialization/OperationPatterns.java
@@ -73,6 +73,22 @@ public abstract class OperationPatterns{
         add(Ops.TRIM, "trim(%s)");
         add(Ops.UPPER, "upper(%s)");
         
+        // date time
+        add(Ops.OpDateTime.SYSDATE, "sysdate");
+        add(Ops.OpDateTime.CURRENT_DATE, "current_date()");
+        add(Ops.OpDateTime.CURRENT_TIME, "current_time()");
+        add(Ops.OpDateTime.CURRENT_TIMESTAMP, "current_timestamp()");
+        add(Ops.OpDateTime.SECOND, "second(%s)");
+        add(Ops.OpDateTime.MINUTE, "minute(%s)");
+        add(Ops.OpDateTime.HOUR, "hour(%s)");
+        add(Ops.OpDateTime.DAY, "day(%s)");
+        add(Ops.OpDateTime.WEEK, "week(%s)");
+        add(Ops.OpDateTime.MONTH, "month(%s)");
+        add(Ops.OpDateTime.YEAR, "year(%s)");
+        add(Ops.OpDateTime.DAY_OF_WEEK, "dayofweek(%s)");
+        add(Ops.OpDateTime.DAY_OF_MONTH, "dayofmonth(%s)");
+        add(Ops.OpDateTime.DAY_OF_YEAR, "dayofyear(%s)");
+        
         // math
         add(Ops.OpMath.ABS,"abs(%s)");
         add(Ops.OpMath.ACOS,"acos(%s)");
@@ -91,8 +107,14 @@ public abstract class OperationPatterns{
         add(Ops.OpMath.MOD,"mod(%s,%s)");
         add(Ops.OpMath.LOG10,"log10(%s)");
         add(Ops.OpMath.LOG,"log(%s)");
-        add(Ops.OpMath.FLOOR,"floor(%s)");
+        add(Ops.OpMath.FLOOR,"floor(%s)");               
         add(Ops.OpMath.EXP,"exp(%s)");
+        
+        // string 
+        add(Ops.OpString.LENGTH, "length(%s)");
+        add(Ops.OpString.LTRIM, "ltrim(%s)");
+        add(Ops.OpString.RTRIM, "rtrim(%s)");
+        add(Ops.OpString.SPACE, "space(%s)");
                 
         // path types
         for (PathType type : new PathType[]{PathMetadata.LISTVALUE, PathMetadata.LISTVALUE_CONSTANT, PathMetadata.MAPVALUE, PathMetadata.MAPVALUE_CONSTANT}){