diff --git a/content/calendar/hackney-empire/alan-davies.md b/content/calendar/hackney-empire/alan-davies.md
index 6ef65fe2..276972a5 100644
--- a/content/calendar/hackney-empire/alan-davies.md
+++ b/content/calendar/hackney-empire/alan-davies.md
@@ -4,7 +4,7 @@ emoji: 🎭
 date: 2024-04-01T12:54:26.902+01:00
 timings:
   - starts: 2024-04-26T20:00:00.000+01:00
-    duration: P3D
+    duration: PT3H
 link: https://www.hackneyempire.co.uk/events/live-at-the-empire-with-alan-davies
 location:
   name: Hackney Empire
diff --git a/content/calendar/one-off/2024-04/brazilian-modernism.md b/content/calendar/one-off/2024-04/brazilian-modernism.md
index b58ad571..5bd9945c 100644
--- a/content/calendar/one-off/2024-04/brazilian-modernism.md
+++ b/content/calendar/one-off/2024-04/brazilian-modernism.md
@@ -5,7 +5,7 @@ date: 2024-04-01T12:29:35.638+01:00
 timings:
   - starts: 2024-04-09T13:00:00.000+01:00
     flexible: true
-    duration: P2D
+    duration: PT2H
 link: https://ravenrow.org/exhibitions/some-may-work-as-symbols-art-made-in-brazil-1950s-70s
 location:
   name: Raven Row
diff --git a/content/calendar/one-off/2024-04/hackney-flea-market.md b/content/calendar/one-off/2024-04/hackney-flea-market.md
index 853a62f3..70e75c02 100644
--- a/content/calendar/one-off/2024-04/hackney-flea-market.md
+++ b/content/calendar/one-off/2024-04/hackney-flea-market.md
@@ -4,7 +4,7 @@ emoji: 🛋️
 date: 2024-04-01T13:20:00.082+01:00
 timings:
   - starts: 2024-04-28T10:00:00.000+01:00
-    duration: P7D
+    duration: PT7H
 link: https://www.eventbrite.co.uk/e/the-giant-london-flea-market-tickets-847335211427?aff=ebdssbdestsearch
 location:
   name: Queen Elizabeth Olympic Park Multi-Storey Car Park