diff --git a/src/internet_monitor.sh b/src/internet_monitor.sh
index b633c5b..034807c 100755
--- a/src/internet_monitor.sh
+++ b/src/internet_monitor.sh
@@ -66,7 +66,7 @@ days_until_next_month() {
 
     if date -v1d -v+1m +%s >/dev/null 2>&1; then
         # macOS/BSD date
-        next_month_ts=$(date -v1d -v+1m +%s)
+        next_month_ts=$(date -v+1m -v1d +%s)
     else
         # GNU date
         next_month_ts=$(date -d "$(date +%Y-%m-01) +1 month" +%s)