diff --git a/.github/workflows/cron-daily-update-nightly.yml b/.github/workflows/cron-semi-weekly-update-nightly.yml
similarity index 96%
rename from .github/workflows/cron-daily-update-nightly.yml
rename to .github/workflows/cron-semi-weekly-update-nightly.yml
index 467abc075..51f7afa2e 100644
--- a/.github/workflows/cron-daily-update-nightly.yml
+++ b/.github/workflows/cron-semi-weekly-update-nightly.yml
@@ -1,7 +1,7 @@
 name: Update Nightly rustc
 on:
   schedule:
-    - cron: "0 0 * * *" # runs daily at 00:00
+    - cron: "0 0 * * 1,4" # runs every Monday and Thursday at 00:00
   workflow_dispatch: # allows manual triggering
 jobs:
   format: