diff --git a/admin-dev/themes/default/template/helpers/calendar/calendar.tpl b/admin-dev/themes/default/template/helpers/calendar/calendar.tpl
index 0f0b375c8..b0591142d 100644
--- a/admin-dev/themes/default/template/helpers/calendar/calendar.tpl
+++ b/admin-dev/themes/default/template/helpers/calendar/calendar.tpl
@@ -49,17 +49,17 @@
 					<div class='form-date-heading'>
 						<span class="checkbox-title">
 							<label >
-								<input type='checkbox' id="datepicker-compare">
+								<input type='checkbox' id="datepicker-compare" name="datepicker_compare"{if isset($compare_date_from) && isset($compare_date_to)} checked="checked"{/if}>
 								{l s='Compare to'}
 							</label>
 						</span>
-						<select id="compare-options" name="compare_date_option" disabled="disabled">
+						<select id="compare-options" name="compare_date_option"{if is_null($compare_date_from) || is_null($compare_date_to)} disabled="disabled"{/if}>
 							<option value="1"{if $compare_option == 1}selected="selected"{/if} label="{l s='Previous period'}">{l s='Previous period'}</option>
 							<option value="2"{if $compare_option == 2}selected="selected"{/if} label="{l s='Previous Year'}">{l s='Previous Year'}</option>
 							<option value="3"{if $compare_option == 3}selected="selected"{/if} label="{l s='Custom'}">{l s='Custom'}</option>
 						</select>
 					</div>
-					<div class="form-date-body" id="form-date-body-compare" style="display: none;">
+					<div class="form-date-body" id="form-date-body-compare"{if is_null($compare_date_from) || is_null($compare_date_to)} style="display: none;"{/if}>
 						<label>{l s='From'}</label>
 						<input id="date-start-compare" class="date-input form-control" type="text" placeholder="Start" name="compare_date_from" value="{$compare_date_from}" />
 						<label>{l s='to'}</label>
@@ -152,10 +152,12 @@
 
 	function setPreviousPeriod() {
 		startDate = parseDate($("#date-start").val(), parseFormat('{$date_format}'));
+		startDate = startDate.setDate(startDate.getDate()-1);
 		endDate = parseDate($("#date-end").val(), parseFormat('{$date_format}'));
-		diff = endDate.getTime() - startDate.getTime();
-		startDateCompare = startDate.getTime()-diff;
-		$("#date-end-compare").val($("#date-start").val());
+		endDate = endDate.setDate(endDate.getDate()-1);
+		diff = endDate - startDate;
+		startDateCompare = startDate-diff;
+		$("#date-end-compare").val(formatDate(new Date(startDate), parseFormat('{$date_format}')));
 		$("#date-start-compare").val(formatDate(new Date(startDateCompare), parseFormat('{$date_format}')));
 	}
 
@@ -238,6 +240,9 @@
 
 		$('#datepicker-compare').click(function() {
 			if ($(this).attr("checked")) {
+				if ($("#date-start-compare").val().replace(/^\s+|\s+$/g, '').length == 0)
+					$('#compare-options').trigger('change');
+
 				datepickerStart.setStartCompare($("#date-start-compare").val());
 				datepickerStart.setEndCompare($("#date-end-compare").val());
 				datepickerEnd.setStartCompare($("#date-start-compare").val());
@@ -266,6 +271,18 @@
 			$('#date-start-compare').focus();
 		});
 
+		if ($('#datepicker-compare').attr("checked"))
+		{
+			if ($("#date-start-compare").val().replace(/^\s+|\s+$/g, '').length == 0)
+				$('#compare-options').trigger('change');
+
+			datepickerStart.setStartCompare($("#date-start-compare").val());
+			datepickerStart.setEndCompare($("#date-end-compare").val());
+			datepickerEnd.setStartCompare($("#date-start-compare").val());
+			datepickerEnd.setEndCompare($("#date-end-compare").val());
+			datepickerStart.setCompare(true);
+			datepickerEnd.setCompare(true);
+		}
 		{/literal}
 	});
 </script>
\ No newline at end of file
diff --git a/classes/Employee.php b/classes/Employee.php
index 22101b92d..b09e4449c 100644
--- a/classes/Employee.php
+++ b/classes/Employee.php
@@ -135,16 +135,16 @@ class EmployeeCore extends ObjectModel
 	public function getFields()
 	{
 		if (empty($this->stats_date_from))
-			$this->stats_date_from = date('Y-m-d 00:00:00');
+			$this->stats_date_from = date('Y-m-d 00:00:00', strtotime("-1 month"));
 
-		if (empty($this->stats_compare_from))
-			$this->stats_compare_from = date('Y-m-d 00:00:00');
+		if (empty($this->stats_compare_from) || $this->stats_compare_from == '0000-00-00')
+			$this->stats_compare_from = null;
 
 		if (empty($this->stats_date_to))
 			$this->stats_date_to = date('Y-m-d 23:59:59');
 
-		if (empty($this->stats_compare_to))
-			$this->stats_compare_to = date('Y-m-d 00:00:00');
+		if (empty($this->stats_compare_to) || $this->stats_compare_to == '0000-00-00')
+			$this->stats_compare_to = null;
 
 		return parent::getFields();
 	}
diff --git a/classes/helper/HelperCalendar.php b/classes/helper/HelperCalendar.php
index 560d4c520..cce35608e 100644
--- a/classes/helper/HelperCalendar.php
+++ b/classes/helper/HelperCalendar.php
@@ -26,7 +26,8 @@
 
 class HelperCalendarCore extends Helper
 {
-	const DEFAULT_DATE_FORMAT = 'Y-m-d';
+	const DEFAULT_DATE_FORMAT    = 'Y-m-d';
+	const DEFAULT_COMPARE_OPTION = 1;
 
 	private $_actions;
 	private $_compare_actions;
@@ -81,41 +82,23 @@ class HelperCalendarCore extends Helper
 
 	public function setCompareDateFrom($value)
 	{
-		if (!isset($value) || $value == '')
-			$value = date('Y-m-d', strtotime("-31 days"));
-
-		if (!is_string($value))
-			throw new PrestaShopException('Date must be a string');
-
 		$this->_compare_date_from = $value;
 		return $this;
 	}
 
 	public function getCompareDateFrom()
 	{
-		if (!isset($this->_compare_date_from))
-			$this->_compare_date_from = date('Y-m-d', strtotime("-31 days"));
-
 		return $this->_compare_date_from;
 	}
 
 	public function setCompareDateTo($value)
 	{
-		if (!isset($value) || $value == '')
-			$value = date('Y-m-d');
-
-		if (!is_string($value))
-			throw new PrestaShopException('Date must be a string');
-
 		$this->_compare_date_to = $value;
 		return $this;
 	}
 
 	public function getCompareDateTo()
 	{
-		if (!isset($this->_compare_date_to))
-			$this->_compare_date_to = date('Y-m-d');
-
 		return $this->_compare_date_to;
 	}
 
diff --git a/controllers/admin/AdminDashboardController.php b/controllers/admin/AdminDashboardController.php
index 0376cf11a..db72a5ddc 100644
--- a/controllers/admin/AdminDashboardController.php
+++ b/controllers/admin/AdminDashboardController.php
@@ -152,10 +152,21 @@ class AdminDashboardControllerCore extends AdminController
 		);
 
 		$calendar_helper = new HelperCalendar();
+
 		$calendar_helper->setDateFrom(Tools::getValue('date_from', $this->context->employee->stats_date_from));
 		$calendar_helper->setDateTo(Tools::getValue('date_to', $this->context->employee->stats_date_to));
-		$calendar_helper->setCompareDateFrom(Tools::getValue('compare_date_from', $this->context->employee->stats_compare_from));
-		$calendar_helper->setCompareDateTo(Tools::getValue('compare_date_to', $this->context->employee->stats_compare_to));
+
+		$stats_compare_from = $this->context->employee->stats_compare_from;
+		$stats_compare_to = $this->context->employee->stats_compare_to;
+
+		if (is_null($stats_compare_from) || $stats_compare_from == '0000-00-00')
+			$stats_compare_from = null;
+
+		if (is_null($stats_compare_to) || $stats_compare_to == '0000-00-00')
+			$stats_compare_to = null;
+
+		$calendar_helper->setCompareDateFrom($stats_compare_from);
+		$calendar_helper->setCompareDateTo($stats_compare_to);
 		$calendar_helper->setCompareOption(Tools::getValue('compare_date_option', $this->context->employee->stats_compare_option));
 
 		$this->tpl_view_vars = array(
@@ -179,9 +190,20 @@ class AdminDashboardControllerCore extends AdminController
 		{
 			$this->context->employee->stats_date_from = Tools::getValue('date_from');
 			$this->context->employee->stats_date_to = Tools::getValue('date_to');
-			$this->context->employee->stats_compare_from = Tools::getValue('compare_date_from');
-			$this->context->employee->stats_compare_to = Tools::getValue('compare_date_to');
-			$this->context->employee->stats_compare_option = Tools::getValue('compare_date_option');
+
+			if (Tools::getValue('datepicker_compare'))
+			{
+				$this->context->employee->stats_compare_from = Tools::getValue('compare_date_from');
+				$this->context->employee->stats_compare_to = Tools::getValue('compare_date_to');
+				$this->context->employee->stats_compare_option = Tools::getValue('compare_date_option');
+			}
+			else
+			{
+				$this->context->employee->stats_compare_from = null;
+				$this->context->employee->stats_compare_to = null;
+				$this->context->employee->stats_compare_option = HelperCalendar::DEFAULT_COMPARE_OPTION;
+			}
+
 			$this->context->employee->update();
 		}
 
diff --git a/install-dev/models/install.php b/install-dev/models/install.php
index a71de5a07..189189485 100644
--- a/install-dev/models/install.php
+++ b/install-dev/models/install.php
@@ -464,10 +464,6 @@ class InstallModelInstall extends InstallAbstractModel
 			$employee->bo_theme = 'default';
 			$employee->default_tab = 1;
 			$employee->active = true;
-			$employee->stats_date_from = date('Y').'-01-01';
-			$employee->stats_date_to = date('Y').'-12-31';
-			$employee->stats_compare_from = date('Y').'-01-01';
-			$employee->stats_compare_to = date('Y').'-12-31';
 			$employee->id_profile = 1;
 			$employee->id_lang = Configuration::get('PS_LANG_DEFAULT');
 			$employee->bo_menu = 1;