diff --git a/Makefile b/Makefile
index 8825f35..8cd35ca 100644
--- a/Makefile
+++ b/Makefile
@@ -27,7 +27,7 @@ update:
 	nix flake update
 	make
 	git add .
-	git commit -S -m "nix flake update: $$(TZ=UTC date +%Y-%m-%d %H:%M:%S %Z))"
+	git commit -S -m "nix flake update: $$(TZ=UTC date '+%Y-%m-%d %H:%M:%S %Z')"
 	git push
 
 fmt:
diff --git a/flake.lock b/flake.lock
index 92109d2..f55c93d 100644
--- a/flake.lock
+++ b/flake.lock
@@ -204,11 +204,11 @@
     },
     "nixpkgs-unstable": {
       "locked": {
-        "lastModified": 1708307464,
-        "narHash": "sha256-OloBg9ZCoPrPqy8/ZoaoRB4kza3lKhnI0LuZq5xldhg=",
+        "lastModified": 1708341091,
+        "narHash": "sha256-3R7doGV1AoB5VKFifEd5elj8t4cld6VpJRpn9NaYr1Y=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "a332040396d7e3c47883e9c115c1da485712805e",
+        "rev": "86ef6bd96b6279e1a4a53236d341f5df1ede3803",
         "type": "github"
       },
       "original": {
@@ -220,11 +220,11 @@
     },
     "nixpkgs_2": {
       "locked": {
-        "lastModified": 1708161998,
-        "narHash": "sha256-6KnemmUorCvlcAvGziFosAVkrlWZGIc6UNT9GUYr0jQ=",
+        "lastModified": 1708294118,
+        "narHash": "sha256-evZzmLW7qoHXf76VCepvun1esZDxHfVRFUJtumD7L2M=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "84d981bae8b5e783b3b548de505b22880559515f",
+        "rev": "e0da498ad77ac8909a980f07eff060862417ccf7",
         "type": "github"
       },
       "original": {