diff --git a/chart-data/json-schema/src/main/resources/CandleData.json b/chart-data/json-schema/src/main/resources/CandleData.json
index 9e2cb48..f1da9db 100644
--- a/chart-data/json-schema/src/main/resources/CandleData.json
+++ b/chart-data/json-schema/src/main/resources/CandleData.json
@@ -3,10 +3,12 @@
   "id" : "CandleData",
   "properties" : {
     "StartDate" : {
-      "type" : "date"
+      "type" : "string",
+      "format" : "date-time"
     },
     "EndDate" : {
-      "type" : "date"
+      "type" : "string",
+      "format" : "date-time"
     },
     "First" :{
 	  "type" : "object",
diff --git a/chart-data/json-schema/src/main/resources/HistoricCandleRequest.json b/chart-data/json-schema/src/main/resources/HistoricCandleRequest.json
index 9381f79..d9c0d75 100644
--- a/chart-data/json-schema/src/main/resources/HistoricCandleRequest.json
+++ b/chart-data/json-schema/src/main/resources/HistoricCandleRequest.json
@@ -30,10 +30,12 @@
 		"$ref" : "./Interval.json"
     },
     "StartDate" : {
-      "type" : "date"
+      "type" : "string",
+      "format" : "date-time"
     },
     "EndDate" : {
-      "type" : "date"
+      "type" : "string",
+      "format" : "date-time"
     },
     "SendingTime" : {
       "type" : "string"