From 2fb900c8eae7dc06482384a64d7c3dd30c4d2390 Mon Sep 17 00:00:00 2001
From: Michael Geers <michael@geers.tv>
Date: Tue, 21 Apr 2026 10:31:19 +0200
Subject: [PATCH] History UI: small fixes (#29138)

---
 assets/js/components/History/Chart.vue | 14 +++++++----
 assets/js/views/History.vue            |  4 ++++
 core/metrics/db.go                     |  7 +++---
 core/metrics/db_test.go                | 33 ++++++++++++++++++++++++++
 4 files changed, 50 insertions(+), 8 deletions(-)

diff --git a/assets/js/components/History/Chart.vue b/assets/js/components/History/Chart.vue
index 874388cf4..4e71801fc 100644
--- a/assets/js/components/History/Chart.vue
+++ b/assets/js/components/History/Chart.vue
@@ -72,10 +72,14 @@ export default defineComponent({
 				const color = colors.palette[i % colors.palette.length];
 				const fill = dimColor(color);
 
-				const points = s.data.map((slot) => ({
-					x: new Date(slot.start).getTime(),
-					y: slotPower(slot, "import") - slotPower(slot, "export"),
-				}));
+				const points = s.data.map((slot) => {
+					const start = new Date(slot.start).getTime();
+					const end = new Date(slot.end).getTime();
+					return {
+						x: (start + end) / 2,
+						y: slotPower(slot, "import") - slotPower(slot, "export"),
+					};
+				});
 
 				return {
 					label: s.name,
@@ -85,7 +89,7 @@ export default defineComponent({
 					fill: true,
 					pointRadius: 0,
 					borderWidth: 1.5,
-					tension: 0.3,
+					tension: 0.05,
 				};
 			});
 
diff --git a/assets/js/views/History.vue b/assets/js/views/History.vue
index 4d818ebca..a346f2d97 100644
--- a/assets/js/views/History.vue
+++ b/assets/js/views/History.vue
@@ -1,6 +1,10 @@
 <template>
 	<div class="container px-4 safe-area-inset">
 		<TopHeader title="History" />
+		<div class="alert alert-light mb-5">
+			This page is for development purposes only. Helps verify logged data. A proper
+			visualization is coming soon, stay tuned.
+		</div>
 		<div class="row">
 			<main class="col-12">
 				<div v-if="loading" class="my-5 text-center text-muted">loading...</div>
diff --git a/core/metrics/db.go b/core/metrics/db.go
index d84fcdffa..a3dba16e1 100644
--- a/core/metrics/db.go
+++ b/core/metrics/db.go
@@ -69,8 +69,10 @@ func QueryImportEnergy(from, to time.Time, aggregate string) ([]Series, error) {
 
 	addDuration := aggregateDurations[aggregate]
 
-	// use Go's tz offset instead of SQLite's 'localtime'
-	tz := time.Now().Format("-07:00")
+	// match timezone of stored timestamps for correct SQLite comparison
+	from = from.Local()
+	to = to.Local()
+	tz := from.Format("-07:00")
 
 	tx := db.Instance.Table("meters m").
 		Select(`e.name AS label, strftime('` + format + `', m.ts, '` + tz + `') AS bucket,
@@ -223,7 +225,6 @@ func importProfile(entity entity, from time.Time) (*[96]float64, error) {
 		return nil, err
 	}
 
-	// use Go's tz offset instead of SQLite's 'localtime'
 	tz := from.Format("-07:00")
 
 	rows, err := db.Query(`SELECT min(ts) AS ts, avg(import) AS import
diff --git a/core/metrics/db_test.go b/core/metrics/db_test.go
index e660395cd..edc8af20b 100644
--- a/core/metrics/db_test.go
+++ b/core/metrics/db_test.go
@@ -47,6 +47,39 @@ func TestSqliteTimestamp(t *testing.T) {
 	require.True(t, clock.Now().Equal(time.Time(ts)), "expected %v, got %v", clock.Now().Local(), time.Time(ts).Local())
 }
 
+func TestQueryImportEnergyUTCFilter(t *testing.T) {
+	require.NoError(t, db.NewInstance("sqlite", ":memory:"))
+	require.NoError(t, SetupSchema())
+
+	e := entity{Name: "grid", Group: "grid"}
+	require.NoError(t, db.Instance.FirstOrCreate(&e).Error)
+
+	// insert 4 slots at 16:00, 16:15, 16:30, 16:45 local time
+	loc := time.Now().Location()
+	base := time.Date(2026, 4, 15, 16, 0, 0, 0, loc)
+
+	for i := range 4 {
+		ts := base.Add(time.Duration(i) * 15 * time.Minute)
+		require.NoError(t, persist(e, ts, 0, float64(i+1)))
+	}
+
+	// query with UTC times that cover all 4 slots
+	// base is 16:00 local, convert to UTC and use a from before and to after
+	from := base.Add(-time.Hour).UTC()
+	to := base.Add(time.Hour).UTC()
+
+	res, err := QueryImportEnergy(from, to, "15m")
+	require.NoError(t, err)
+	require.Len(t, res, 1)
+	require.Len(t, res[0].Data, 4, "expected all 4 slots, got %d", len(res[0].Data))
+
+	var totalExport float64
+	for _, s := range res[0].Data {
+		totalExport += s.Export
+	}
+	require.InDelta(t, 1+2+3+4, totalExport, 0.001)
+}
+
 func TestUpdateProfile(t *testing.T) {
 	clock := clock.NewMock()