diff --git a/src/common/datetime/calc_date_range.ts b/src/common/datetime/calc_date_range.ts
index 79a2d729d0..1d7580cae6 100644
--- a/src/common/datetime/calc_date_range.ts
+++ b/src/common/datetime/calc_date_range.ts
@@ -93,8 +93,8 @@ export const calcDateRange = (
       ];
     case "now-12m":
       return [
-        calcDate(subMonths(today, 12), startOfMonth, hass.locale, hass.config),
-        calcDate(subMonths(today, 1), endOfMonth, hass.locale, hass.config),
+        calcDate(today, subMonths, hass.locale, hass.config, 12),
+        calcDate(today, subMonths, hass.locale, hass.config, 0),
       ];
     case "now-1h":
       return [