diff --git a/degesch.c b/degesch.c
index 58bbbb0..2388080 100644
--- a/degesch.c
+++ b/degesch.c
@@ -9035,9 +9035,10 @@ static void
 rearm_date_change_timer (struct app_context *ctx)
 {
 	const time_t seconds_per_day = 60 * 60 * 12;
-	poller_timer_set (&ctx->date_chg_tmr,
-		(time (NULL) + seconds_per_day - 1)
-		/ seconds_per_day * seconds_per_day * 1000);
+	const time_t now = time (NULL);
+	const time_t midnight = (now + seconds_per_day - 1)
+		/ seconds_per_day * seconds_per_day;
+	poller_timer_set (&ctx->date_chg_tmr, (midnight - now) * 1000);
 }
 
 static void