diff --git a/CHANGELOG.md b/CHANGELOG.md
index c723f3b..2f28474 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ Software updates:
 
 System:
 
+* Nightly backups now occur on a random minute in the 3am hour (in the system time zone). The minute is chosen during Mail-in-a-Box installation/upgrade and remains the same until the next upgrade.
 * Fix for mail log statistics report on leap days.
 * Fix Mozilla autoconfig useGlobalPreferredServer setting.
 
diff --git a/setup/management.sh b/setup/management.sh
index 3caf8ee..9d7c762 100755
--- a/setup/management.sh
+++ b/setup/management.sh
@@ -101,10 +101,11 @@ hide_output systemctl enable mailinabox.service
 # Perform nightly tasks at 3am in system time: take a backup, run
 # status checks and email the administrator any changes.
 
+minute=$((RANDOM % 60))  # avoid overloading mailinabox.email
 cat > /etc/cron.d/mailinabox-nightly << EOF;
 # Mail-in-a-Box --- Do not edit / will be overwritten on update.
 # Run nightly tasks: backup, status checks.
-0 3 * * *	root	(cd `pwd` && management/daily_tasks.sh)
+$minute 3 * * *	root	(cd `pwd` && management/daily_tasks.sh)
 EOF
 
 # Start the management server.