diff --git a/content/activities/201402-cryptoparty.md b/content/activities/201402-cryptoparty.md
index 129bae9e..be3cbc6d 100644
--- a/content/activities/201402-cryptoparty.md
+++ b/content/activities/201402-cryptoparty.md
@@ -1,6 +1,6 @@
 ---
 kind: event
-startdate: 2014-02-08T15:00:00
+startdate: 2014-02-08T15:00:00Z
 duration: 4h
 title: "Cryptoparty in der Stadtbibliothek"
 location:
diff --git a/content/activities/201402-safer-internet-day-tor.md b/content/activities/201402-safer-internet-day-tor.md
index c7409ac2..047d9d8d 100644
--- a/content/activities/201402-safer-internet-day-tor.md
+++ b/content/activities/201402-safer-internet-day-tor.md
@@ -1,6 +1,6 @@
 ---
 kind: event
-startdate: 2014-02-11T19:00:00
+startdate: 2014-02-11T19:30:00Z
 duration: 90m
 title: "Vortrag: Anonym im Netz mit Tor"
 speakers: