diff --git a/build-rpi.sh b/build-rpi.sh
index d1a51f6..dc2c402 100755
--- a/build-rpi.sh
+++ b/build-rpi.sh
@@ -11,7 +11,7 @@ for arg in "$@"; do
     esac
 done
 
-TIMESTAMP=$(date +"%m%d%Y-%H%M")
+TIMESTAMP=$(date +"%Y-%m-%d_%H-%M-%S")
 FILENAME="radiantwave-kiosk-rpi${VARIANT}_${TIMESTAMP}.img.zst"
 REPO="$(pwd)"
 NIX_STORE="kiosk-nix-store"