diff --git a/flake.nix b/flake.nix
index 182e6dd..a895565 100644
--- a/flake.nix
+++ b/flake.nix
@@ -223,7 +223,7 @@
             partOf      = [ "${cfg.user}_new_users.service" ];
             timerConfig = {
               # every 15 min
-              OnCalendar  = "*-*-* *:0/15:00";
+              OnCalendar  = "*:0/15";
               Unit        = "${cfg.user}_update.service";
             };
           };