From 881f5e5012ffd36bedc455b71efa249ba7a51f32 Mon Sep 17 00:00:00 2001
From: Bram Kragten <mail@bramkragten.nl>
Date: Wed, 31 May 2023 12:42:03 +0200
Subject: [PATCH] Fix energy compare (#16687)

---
 src/data/energy.ts | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/data/energy.ts b/src/data/energy.ts
index a36500d1b1..151089d929 100644
--- a/src/data/energy.ts
+++ b/src/data/energy.ts
@@ -1,6 +1,8 @@
 import {
+  addDays,
   addHours,
   addMilliseconds,
+  addMonths,
   differenceInDays,
   endOfToday,
   endOfYesterday,
@@ -414,11 +416,17 @@ const getEnergyData = async (
   let _waterStatsCompare: Statistics | Promise<Statistics> = {};
 
   if (compare) {
+    if (dayDifference > 27 && dayDifference < 32) {
+      // When comparing a month, we want to start at the begining of the month
+      startCompare = addMonths(start, -1);
+    } else {
+      startCompare = addDays(start, (dayDifference + 1) * -1);
+    }
     endCompare = addMilliseconds(start, -1);
     if (energyStatIds.length) {
       _energyStatsCompare = fetchStatistics(
         hass!,
-        start,
+        startCompare,
         endCompare,
         energyStatIds,
         period,
@@ -429,7 +437,7 @@ const getEnergyData = async (
     if (waterStatIds.length) {
       _waterStatsCompare = fetchStatistics(
         hass!,
-        start,
+        startCompare,
         endCompare,
         waterStatIds,
         period,