diff --git a/responses.go b/responses.go
index 81cc060..cc6ae4a 100644
--- a/responses.go
+++ b/responses.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"fmt"
 	"strconv"
 	"time"
 
@@ -15,6 +16,14 @@ func init() {
 			return APIErrorResponse{err: err}
 		}
 
+		// Check the survey is open
+		now := time.Now()
+		if now.Before(s.StartAvailability) {
+			return APIErrorResponse{err: fmt.Errorf("Le questionnaire n'a pas encore commencé")}
+		} else if now.After(s.EndAvailability) {
+			return APIErrorResponse{err: fmt.Errorf("Le questionnaire n'est plus ouvert")}
+		}
+
 		for _, response := range responses {
 			if len(response.Answer) > 0 {
 				if _, err := s.NewResponse(response.IdQuestion, u.Id, response.Answer); err != nil {