diff --git a/.jvmopts b/.jvmopts
index 16053bcbf3a..1741d193910 100644
--- a/.jvmopts
+++ b/.jvmopts
@@ -1,6 +1,6 @@
 -Xmx8G
 -XX:ReservedCodeCacheSize=128m
 -XX:NewRatio=4
--Duser.timezone=Australia/Sydney
+-Duser.timezone=Australia/Sydney # because it is too easy for devs to forget about timezones, see https://github.com/guardian/frontend/pull/4713
 -DSTAGE=DEV
 -DAPP_SECRET=this_is_not_a_real_secret_just_for_tests