diff --git a/forms/DatetimeField.php b/forms/DatetimeField.php
index f44108cd7..6d4342b0c 100644
--- a/forms/DatetimeField.php
+++ b/forms/DatetimeField.php
@@ -148,7 +148,7 @@ class DatetimeField extends FormField {
 					unset($userValueObj);
 				} else {
 					// Validation happens later, so set the raw string in case Zend_Date doesn't accept it
-					$this->value = sprintf($this->getConfig('datetimeorder'), $val['date'], $val['time']);
+					$this->value = trim(sprintf($this->getConfig('datetimeorder'), $val['date'], $val['time']));
 				}
 				
 				if($userTz) date_default_timezone_set($dataTz);
diff --git a/model/fieldtypes/Date.php b/model/fieldtypes/Date.php
index 736179911..bd7048f87 100644
--- a/model/fieldtypes/Date.php
+++ b/model/fieldtypes/Date.php
@@ -21,17 +21,26 @@
 class Date extends DBField {
 	
 	function setValue($value) {
+		if($value === false || $value === null || (is_string($value) && !strlen($value))) {
+			// don't try to evaluate empty values with strtotime() below, as it returns "1970-01-01" when it should be saved as NULL in database
+			$this->value = null;
+			return;
+		}
+
 		// @todo This needs tidy up (what if you only specify a month and a year, for example?)
 		if(is_array($value)) {
 			if(!empty($value['Day']) && !empty($value['Month']) && !empty($value['Year'])) {
 				$this->value = $value['Year'] . '-' . $value['Month'] . '-' . $value['Day'];
 				return;
+			} else {
+				// return nothing (so checks below don't fail on an empty array)
+				return null;
 			}
 		}
 		
 		// Default to NZ date format - strtotime expects a US date
 		if(ereg('^([0-9]+)/([0-9]+)/([0-9]+)$', $value, $parts)) {
-			$value = "$parts[2]/$parts[1]/$parts[3]";			
+			$value = "$parts[2]/$parts[1]/$parts[3]";
 		}
 		
 		if(is_numeric($value)) {
@@ -84,13 +93,18 @@ class Date extends DBField {
 	}
 
 	/**
-	 * Returns the date of the month
+	 * Returns the day of the month.
+	 * @param boolean $includeOrdinals Include ordinal suffix to day, e.g. "th" or "rd"
+	 * @return string
 	 */
-	function DayOfMonth() {
-		if($this->value) return date('j', strtotime($this->value));
+	function DayOfMonth($includeOrdinal = false) {
+		if($this->value) {
+			$format = 'j';
+			if ($includeOrdinal) $format .= 'S';
+			return date($format, strtotime($this->value));
+		}
 	}
 	
-	
 	/**
 	 * Returns the date in the format 24 December 2006
 	 */
@@ -121,7 +135,7 @@ class Date extends DBField {
 	 * strftime obeys the current LC_TIME/LC_ALL when printing lexical values
 	 * like day- and month-names
 	 */
-	function FormatI18N($formattingString) {		
+	function FormatI18N($formattingString) {
 		if($this->value) {
 			$fecfrm = strftime($formattingString, strtotime($this->value));
 			return utf8_encode($fecfrm);
@@ -130,10 +144,13 @@ class Date extends DBField {
 	
 	/*
 	 * Return a string in the form "12 - 16 Sept" or "12 Aug - 16 Sept"
+	 * @param Date $otherDateObj Another date object specifying the end of the range
+	 * @param boolean $includeOrdinals Include ordinal suffix to day, e.g. "th" or "rd"
+	 * @return string
 	 */
-	function RangeString($otherDateObj) {
-		$d1 = $this->DayOfMonth();
-		$d2 = $otherDateObj->DayOfMonth();
+	function RangeString($otherDateObj, $includeOrdinals = false) {
+		$d1 = $this->DayOfMonth($includeOrdinals);
+		$d2 = $otherDateObj->DayOfMonth($includeOrdinals);
 		$m1 = $this->ShortMonth();
 		$m2 = $otherDateObj->ShortMonth();
 		$y1 = $this->Year();
@@ -357,4 +374,4 @@ class Date extends DBField {
 	public function scaffoldFormField($title = null, $params = null) {
 		return new DateField($this->name, $title);
 	}
-}
\ No newline at end of file
+}
diff --git a/model/fieldtypes/Datetime.php b/model/fieldtypes/Datetime.php
index 77a56688a..83cb184e2 100644
--- a/model/fieldtypes/Datetime.php
+++ b/model/fieldtypes/Datetime.php
@@ -26,6 +26,12 @@
 class SS_Datetime extends Date {
 	
 	function setValue($value) {
+		if($value === false || $value === null || (is_string($value) && !strlen($value))) {
+			// don't try to evaluate empty values with strtotime() below, as it returns "1970-01-01" when it should be saved as NULL in database
+			$this->value = null;
+			return;
+		}
+
 		// Default to NZ date format - strtotime expects a US date
 		if(ereg('^([0-9]+)/([0-9]+)/([0-9]+)$', $value, $parts)) {
 			$value = "$parts[2]/$parts[1]/$parts[3]";
@@ -42,19 +48,23 @@ class SS_Datetime extends Date {
 	 * Returns the date in the raw SQL-format, e.g. “2006-01-18 16:32:04”
 	 */
 	function Nice() {
-		return date('d/m/Y g:ia', strtotime($this->value));
+		if($this->value) return date('d/m/Y g:ia', strtotime($this->value));
 	}
+
 	function Nice24() {
-		return date('d/m/Y H:i', strtotime($this->value));
+		if($this->value) return date('d/m/Y H:i', strtotime($this->value));
 	}
+
 	function Date() {
-		return date('d/m/Y', strtotime($this->value));
+		if($this->value) return date('d/m/Y', strtotime($this->value));
 	}
+
 	function Time() {
-		return date('g:ia', strtotime($this->value));
+		if($this->value) return date('g:ia', strtotime($this->value));
 	}
+
 	function Time24() {
-		return date('H:i', strtotime($this->value));
+		if($this->value) return date('H:i', strtotime($this->value));
 	}
 
 	function requireField() {
@@ -64,7 +74,7 @@ class SS_Datetime extends Date {
 	}
 	
 	function URLDatetime() {
-		return date('Y-m-d%20H:i:s', strtotime($this->value));
+		if($this->value) return date('Y-m-d%20H:i:s', strtotime($this->value));
 	}
 	
 	public function scaffoldFormField($title = null, $params = null) {
diff --git a/tests/model/DateTest.php b/tests/model/DateTest.php
index 44b1b498d..f09da2c86 100644
--- a/tests/model/DateTest.php
+++ b/tests/model/DateTest.php
@@ -93,5 +93,35 @@ class DateTest extends SapphireTest {
 			"Date->Long() works with D/M/YYYY"
 		);
 	}
-	
+
+	function testSetNullAndZeroValues() {
+		$date = DBField::create('Date', '');
+		$this->assertNull($date->getValue(), 'Empty string evaluates to NULL');
+
+		$date = DBField::create('Date', null);
+		$this->assertNull($date->getValue(), 'NULL is set as NULL');
+
+		$date = DBField::create('Date', false);
+		$this->assertNull($date->getValue(), 'Boolean FALSE evaluates to NULL');
+
+		$date = DBField::create('Date', array());
+		$this->assertNull($date->getValue(), 'Empty array evaluates to NULL');
+
+		$date = DBField::create('Date', '0');
+		$this->assertEquals('1970-01-01', $date->getValue(), 'Zero is UNIX epoch date');
+
+		$date = DBField::create('Date', 0);
+		$this->assertEquals('1970-01-01', $date->getValue(), 'Zero is UNIX epoch date');
+	}
+
+	function testDayOfMonth() {
+		$date = DBField::create('Date', '2000-10-10');
+		$this->assertEquals('10', $date->DayOfMonth());
+		$this->assertEquals('10th', $date->DayOfMonth(true));
+
+		$range = $date->RangeString(DBField::create('Date', '2000-10-20'));
+		$this->assertEquals('10 - 20 Oct 2000', $range);
+		$range = $date->RangeString(DBField::create('Date', '2000-10-20'), true);
+		$this->assertEquals('10th - 20th Oct 2000', $range);
+	}
 }
diff --git a/tests/model/DatetimeTest.php b/tests/model/DatetimeTest.php
index b18c6fb01..f3636ef6a 100644
--- a/tests/model/DatetimeTest.php
+++ b/tests/model/DatetimeTest.php
@@ -33,4 +33,22 @@ class SS_DatetimeTest extends SapphireTest {
 		$nowDatetime = SS_Datetime::now();
 		$this->assertEquals($systemDatetime->Date(), $nowDatetime->Date());
 	}
-}
\ No newline at end of file
+
+	function testSetNullAndZeroValues() {
+		$date = DBField::create('SS_Datetime', '');
+		$this->assertNull($date->getValue(), 'Empty string evaluates to NULL');
+
+		$date = DBField::create('SS_Datetime', null);
+		$this->assertNull($date->getValue(), 'NULL is set as NULL');
+
+		$date = DBField::create('SS_Datetime', false);
+		$this->assertNull($date->getValue(), 'Boolean FALSE evaluates to NULL');
+
+		$date = DBField::create('SS_Datetime', '0');
+		$this->assertEquals('1970-01-01 12:00:00', $date->getValue(), 'Zero is UNIX epoch time');
+
+		$date = DBField::create('SS_Datetime', 0);
+		$this->assertEquals('1970-01-01 12:00:00', $date->getValue(), 'Zero is UNIX epoch time');
+	}
+
+}