diff --git a/.github/workflows/mac.yml b/.github/workflows/mac.yml
index cfa13fa21..236470508 100644
--- a/.github/workflows/mac.yml
+++ b/.github/workflows/mac.yml
@@ -42,7 +42,7 @@ jobs:
       run: |
         git ls-tree -r --name-only HEAD | while read filename; do
           TS="$(git log -1 --format="%ct" -- ${filename})"
-          touch "${filename}" -mt "$(date --date="@$TS" "+%Y%m%d%H%M.%S")"
+          touch "${filename}" -mt "$(date -r "$TS" "+%Y%m%d%H%M.%S")"
         done
 
     # things to be cached/restored: