diff --git a/src/Etsy/EtsyApi.php b/src/Etsy/EtsyApi.php
index 06b8fa7..303e1af 100644
--- a/src/Etsy/EtsyApi.php
+++ b/src/Etsy/EtsyApi.php
@@ -96,13 +96,18 @@ protected function validateResponse($request_args, $response)
 	private function prepareData($data) {
 		$result = array();
 		foreach ($data as $key => $value) {
-			$type = gettype($value);
-			if ($type !== 'boolean') {
-				$result[$key] = $value;
-				continue;
-			}
-
-			$result[$key] = $value ? 1 : 0;
+            $type = gettype($value);
+            switch ($type) {
+                case 'boolean':
+                    $result[$key] = $value ? 1 : 0;
+                    break;
+                case 'array':
+                    $result[$key] = implode(',', $value);
+                    break;
+                default:
+                	$result[$key] = $value;
+                    break;
+            }
 		}
 
 		return $result;
diff --git a/src/Etsy/RequestValidator.php b/src/Etsy/RequestValidator.php
index f32277c..28ef489 100644
--- a/src/Etsy/RequestValidator.php
+++ b/src/Etsy/RequestValidator.php
@@ -88,7 +88,7 @@ public static function validateData($args, $methodInfo)
 								{
 									$valueTypes[] = self::transformValueType(gettype($value));
 								}
-								$type = 'map(' . implode($valueTypes, ', ') . ')';
+								$type = 'map(' . implode(', ', $valueTypes) . ')';
 								break;
 							}
 
@@ -110,7 +110,9 @@ public static function validateData($args, $methodInfo)
 				}
 
                 if ($validType !== $type) {
-                    if (substr($validType, 0, 4) === 'enum') {
+                    if ('epoch' === $validType && false !== strtotime($arg)) {
+                        $result['_valid'][$name] = $arg;
+                    } elseif (substr($validType, 0, 4) === 'enum') {
                         if ($arg === 'enum' || !preg_match("@" . preg_quote($arg) . "@", $validType)) {
                             $result['_invalid'][] = 'Invalid enum data param "' . $name . '" value (' . $arg . '): valid values "' . $validType . '"';
                         } else {
diff --git a/src/Etsy/methods.json b/src/Etsy/methods.json
index 988fff8..181f5b2 100644
--- a/src/Etsy/methods.json
+++ b/src/Etsy/methods.json
@@ -471,7 +471,7 @@
       "tags": "array(string)",
       "who_made": "enum(i_did, collective, someone_else)",
       "is_supply": "boolean",
-      "when_made": "enum(made_to_order, 2020_2020, 2010_2019, 2001_2009, before_2001, 2000_2000, 1990s, 1980s, 1970s, 1960s, 1950s, 1940s, 1930s, 1920s, 1910s, 1900s, 1800s, 1700s, before_1700)",
+      "when_made": "enum(made_to_order, 2020_2021, 2010_2019, 2002_2009, before_2002, 2000_2001, 1990s, 1980s, 1970s, 1960s, 1950s, 1940s, 1930s, 1920s, 1910s, 1900s, 1800s, 1700s, before_1700)",
       "recipient": "enum(men, women, unisex_adults, teen_boys, teen_girls, teens, boys, girls, children, baby_boys, baby_girls, babies, birds, cats, dogs, pets, not_specified)",
       "occasion": "enum(anniversary, baptism, bar_or_bat_mitzvah, birthday, canada_day, chinese_new_year, cinco_de_mayo, confirmation, christmas, day_of_the_dead, easter, eid, engagement, fathers_day, get_well, graduation, halloween, hanukkah, housewarming, kwanzaa, prom, july_4th, mothers_day, new_baby, new_years, quinceanera, retirement, st_patricks_day, sweet_16, sympathy, thanksgiving, valentines, wedding)",
       "style": "array(string)",
@@ -2607,8 +2607,8 @@
       "shop_id": "shop_id_or_name",
       "min_created": "epoch",
       "max_created": "epoch",
-      "min_last_modified": "int",
-      "max_last_modified": "int",
+      "min_last_modified": "epoch",
+      "max_last_modified": "epoch",
       "limit": "int",
       "offset": "int",
       "page": "int",