Use a formatter in the NSDatePickerCell.

Headers/AppKit/NSDatePickerCell.h

@@ -60,17 +60,15 @@ enum {
 };
 typedef NSUInteger NSDatePickerElementFlags;
 
+@class NSColor, NSDate, NSCalendar, NSLocale, NSTimeZone;
+
 @interface NSDatePickerCell : NSActionCell
 {
   NSColor *_backgroundColor;
-  NSCalendar *_calendar;
-  NSDate *_dateValue;
-  id _delegate;
-  NSLocale *_locale;
+  NSColor *_textColor;
   NSDate *_maxDate;
   NSDate *_minDate;
-  NSColor *_textColor;
-  NSTimeZone *_timeZone;
+  id _delegate;
   NSTimeInterval _timeInterval;
   // FIXME: pack into a bitfield?
   NSDatePickerElementFlags _datePickerElements;

Source/NSDatePickerCell.m

@@ -30,11 +30,25 @@
 */
 
 #import <Foundation/NSString.h>
+#import <Foundation/NSDateFormatter.h>
 #import <AppKit/NSDatePickerCell.h>
 #import <AppKit/NSColor.h>
 
 @implementation NSDatePickerCell
 
+- (id) initTextCell: (NSString*)aString
+{
+  if ((self = [super  initTextCell: aString]))
+    {
+      NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
+
+      [self setFormatter: formatter];
+      RELEASE(formatter);
+    }
+
+  return self;
+}
+
 - (NSColor *) backgroundColor
 {
   return _backgroundColor;
@@ -47,12 +61,12 @@
 
 - (NSCalendar *) calendar
 {
-  return _calendar;
+  return [[self formatter] calendar];
 }
 
 - (void) setCalendar: (NSCalendar *)calendar
 {
-  ASSIGN(_calendar, calendar);
+  [[self formatter] setCalendar: calendar];
 }
 
 - (NSDatePickerElementFlags) datePickerElements
@@ -117,12 +131,12 @@
 
 - (NSLocale *) locale
 {
-  return _locale;
+  return [[self formatter] locale];
 }
 
 - (void) setLocale: (NSLocale *)locale
 {
-  ASSIGN(_locale, locale);
+  [[self formatter] setLocale: locale];
 }
 
 - (NSDate *) maxDate
@@ -167,12 +181,12 @@
 
 - (NSTimeZone *) timeZone
 {
-  return _timeZone;
+  return [[self formatter] timeZone];
 }
 
 - (void) setTimeZone: (NSTimeZone *)zone
 {
-  ASSIGN(_timeZone, zone);
+  [[self formatter] setTimeZone: zone];
 }
 
 - (void) encodeWithCoder: (NSCoder *)aCoder