diff --git a/scripts/metobs_config.sh b/scripts/metobs_config.sh
index 11f4c2c425b5e81a2807147443cd5c687f7ec316..1138cba120246715e22ec75ffa5d84e1fdb4dfea 100644
--- a/scripts/metobs_config.sh
+++ b/scripts/metobs_config.sh
@@ -24,7 +24,7 @@ oops() {
 }
 
 day_before() {
-    date %Y%m%d --date "$1 -1 day"
+    date +%Y%m%d --date "$1 -1 day" || oops "Could not get day before"
 }
 
 work_dir() {