diff --git a/lib/blocks.js b/lib/blocks.js
index 8b15f16..1c102df 100644
--- a/lib/blocks.js
+++ b/lib/blocks.js
@@ -89,6 +89,11 @@ BlockController.prototype.list = function(req, res) {
 
   if (req.query.blockDate) {
     dateStr = req.query.blockDate;
+    var datePattern = /\d{4}-\d{2}-\d{2}/;
+    if(!datePattern.test(dateStr)) {
+      return common.handleErrors(new Error('Please use yyyy-mm-dd format'), res);
+    }
+
     isToday = dateStr === todayStr;
   } else {
     dateStr = todayStr;