diff --git a/pkg/customcost/querier.go b/pkg/customcost/querier.go
index a100b0d3e..e1a2da612 100644
--- a/pkg/customcost/querier.go
+++ b/pkg/customcost/querier.go
@@ -2,9 +2,95 @@ package customcost
 
 import (
 	"context"
+	"fmt"
+	"time"
+
+	"github.com/opencost/opencost/core/pkg/opencost"
+	"github.com/opencost/opencost/core/pkg/util/timeutil"
+	"github.com/opencost/opencost/pkg/env"
 )
 
 type Querier interface {
 	QueryTotal(ctx context.Context, request CostTotalRequest) (*CostResponse, error)
 	QueryTimeseries(ctx context.Context, request CostTimeseriesRequest) (*CostTimeseriesResponse, error)
 }
+
+func GetCustomCostWindowAccumulation(window opencost.Window, accumulate opencost.AccumulateOption) (opencost.Window, opencost.AccumulateOption, error) {
+	var err error
+	if accumulate == opencost.AccumulateOptionNone {
+		accumulate, err = getCustomCostAccumulateOption(window, nil)
+		if err != nil {
+			return opencost.Window{}, opencost.AccumulateOptionNone, fmt.Errorf("failed to determine custom cost accumulation option: %v", err)
+		}
+	}
+	window, err = window.GetAccumulateWindow(accumulate)
+	if err != nil {
+		return opencost.Window{}, opencost.AccumulateOptionNone, fmt.Errorf("failed to determine custom cost accumulation option: %v", err)
+	}
+
+	return window, accumulate, nil
+}
+
+// getCustomCostAccumulateOption determines defaults in a way that matches options presented in the UI
+func getCustomCostAccumulateOption(window opencost.Window, from []opencost.AccumulateOption) (opencost.AccumulateOption, error) {
+	if window.IsOpen() || window.IsNegative() {
+		return opencost.AccumulateOptionNone, fmt.Errorf("invalid window '%s'", window.String())
+	}
+
+	if len(from) == 0 {
+		from = allSteppedAccumulateOptions
+	}
+
+	hourlyStoreHours := env.GetDataRetentionHourlyResolutionHours()
+	hourlySteps := time.Duration(hourlyStoreHours) * time.Hour
+	oldestHourly := time.Now().Add(-1 * hourlySteps)
+
+	// Use hourly if...
+	//  (1) hourly is an option;
+	//  (2) we have hourly store coverage; and
+	//  (3) the window duration is less than the hourly break point.
+	if hasHourly(from) && oldestHourly.Before(*window.Start()) && window.Duration() <= hourlySteps {
+		return opencost.AccumulateOptionHour, nil
+	}
+
+	dailyStoreDays := env.GetDataRetentionDailyResolutionDays()
+	dailySteps := time.Duration(dailyStoreDays) * timeutil.Day
+	oldestDaily := time.Now().Add(-1 * dailySteps)
+	// Use daily if...
+	//  (1) daily is an option
+	// It is acceptable to query a range for which we only have partial data
+	if hasDaily(from) {
+		return opencost.AccumulateOptionDay, nil
+	}
+
+	if oldestDaily.After(*window.Start()) {
+		return opencost.AccumulateOptionDay, fmt.Errorf("data store does not have coverage for %v", window)
+	}
+
+	return opencost.AccumulateOptionNone, fmt.Errorf("no valid accumulate option in %v for %s", from, window)
+}
+
+var allSteppedAccumulateOptions = []opencost.AccumulateOption{
+	opencost.AccumulateOptionHour,
+	opencost.AccumulateOptionDay,
+}
+
+func hasHourly(opts []opencost.AccumulateOption) bool {
+	for _, opt := range opts {
+		if opt == opencost.AccumulateOptionHour {
+			return true
+		}
+	}
+
+	return false
+}
+
+func hasDaily(opts []opencost.AccumulateOption) bool {
+	for _, opt := range opts {
+		if opt == opencost.AccumulateOptionDay {
+			return true
+		}
+	}
+
+	return false
+}
diff --git a/pkg/customcost/repositoryquerier.go b/pkg/customcost/repositoryquerier.go
index 8e7c27e96..bbb7bc5a0 100644
--- a/pkg/customcost/repositoryquerier.go
+++ b/pkg/customcost/repositoryquerier.go
@@ -8,7 +8,6 @@ import (
 
 	"github.com/opencost/opencost/core/pkg/opencost"
 	"github.com/opencost/opencost/core/pkg/util/timeutil"
-	"github.com/opencost/opencost/pkg/env"
 )
 
 type RepositoryQuerier struct {
@@ -28,9 +27,15 @@ func NewRepositoryQuerier(hourlyRepo, dailyRepo Repository, hourlyDuration, dail
 }
 
 func (rq *RepositoryQuerier) QueryTotal(ctx context.Context, request CostTotalRequest) (*CostResponse, error) {
+	window := opencost.NewClosedWindow(request.Start, request.End)
+	window, accumulate, err := GetCustomCostWindowAccumulation(window, request.Accumulate)
+	if err != nil {
+		return nil, fmt.Errorf("error getting custom cost total window accumulation: %w", err)
+	}
+
 	repo := rq.dailyRepo
 	step := timeutil.Day
-	if request.Accumulate == opencost.AccumulateOptionHour {
+	if accumulate == opencost.AccumulateOptionHour {
 		repo = rq.hourlyRepo
 		step = time.Hour
 	}
@@ -45,10 +50,9 @@ func (rq *RepositoryQuerier) QueryTotal(ctx context.Context, request CostTotalRe
 		return nil, fmt.Errorf("RepositoryQuerier: Query: failed to compile filters: %w", err)
 	}
 
-	requestWindow := opencost.NewClosedWindow(request.Start, request.End)
-	ccs := NewCustomCostSet(requestWindow)
-	queryStart := request.Start
-	for queryStart.Before(request.End) {
+	ccs := NewCustomCostSet(window)
+	queryStart := *window.Start()
+	for queryStart.Before(*window.End()) {
 		queryEnd := queryStart.Add(step)
 
 		for _, domain := range domains {
@@ -78,81 +82,14 @@ func (rq *RepositoryQuerier) QueryTotal(ctx context.Context, request CostTotalRe
 	return NewCostResponse(ccs), nil
 }
 
-var allSteppedAccumulateOptions = []opencost.AccumulateOption{
-	opencost.AccumulateOptionHour,
-	opencost.AccumulateOptionDay,
-}
-
-func hasHourly(opts []opencost.AccumulateOption) bool {
-	for _, opt := range opts {
-		if opt == opencost.AccumulateOptionHour {
-			return true
-		}
-	}
-
-	return false
-}
-
-func hasDaily(opts []opencost.AccumulateOption) bool {
-	for _, opt := range opts {
-		if opt == opencost.AccumulateOptionDay {
-			return true
-		}
-	}
-
-	return false
-}
-
-// GetCustomCostAccumulateOption determines defaults in a way that matches options presented in the UI
-func GetCustomCostAccumulateOption(window opencost.Window, from []opencost.AccumulateOption) (opencost.AccumulateOption, error) {
-	if window.IsOpen() || window.IsNegative() {
-		return opencost.AccumulateOptionNone, fmt.Errorf("invalid window '%s'", window.String())
-	}
-
-	if len(from) == 0 {
-		from = allSteppedAccumulateOptions
-	}
-
-	hourlyStoreHours := env.GetDataRetentionHourlyResolutionHours()
-	hourlySteps := time.Duration(hourlyStoreHours) * time.Hour
-	oldestHourly := time.Now().Add(-1 * hourlySteps)
-
-	// Use hourly if...
-	//  (1) hourly is an option;
-	//  (2) we have hourly store coverage; and
-	//  (3) the window duration is less than the hourly break point.
-	if hasHourly(from) && oldestHourly.Before(*window.Start()) && window.Duration() <= hourlySteps {
-		return opencost.AccumulateOptionHour, nil
-	}
-
-	dailyStoreDays := env.GetDataRetentionDailyResolutionDays()
-	dailySteps := time.Duration(dailyStoreDays) * timeutil.Day
-	oldestDaily := time.Now().Add(-1 * dailySteps)
-	// Use daily if...
-	//  (1) daily is an option
-	// It is acceptable to query a range for which we only have partial data
-	if hasDaily(from) {
-		return opencost.AccumulateOptionDay, nil
-	}
-
-	if oldestDaily.After(*window.Start()) {
-		return opencost.AccumulateOptionNone, fmt.Errorf("data store does not have coverage for %v", window)
-	}
-
-	return opencost.AccumulateOptionNone, fmt.Errorf("no valid accumulate option in %v for %s", from, window)
-}
-
 func (rq *RepositoryQuerier) QueryTimeseries(ctx context.Context, request CostTimeseriesRequest) (*CostTimeseriesResponse, error) {
-	window, _ := opencost.NewClosedWindow(request.Start, request.End).GetAccumulateWindow(request.Accumulate)
-	var err error
-	if request.Accumulate == opencost.AccumulateOptionNone {
-		request.Accumulate, err = GetCustomCostAccumulateOption(window, nil)
-		if err != nil {
-			return nil, fmt.Errorf("error determining accumulation option: %v", err)
-		}
+	window := opencost.NewClosedWindow(request.Start, request.End)
+	window, accumulate, err := GetCustomCostWindowAccumulation(window, request.Accumulate)
+	if err != nil {
+		return nil, fmt.Errorf("error getting custom cost timeseries window accumulation: %w", err)
 	}
 
-	windows, err := window.GetAccumulateWindows(request.Accumulate)
+	windows, err := window.GetAccumulateWindows(accumulate)
 	if err != nil {
 		return nil, fmt.Errorf("error getting timeseries windows: %w", err)
 	}
@@ -172,7 +109,7 @@ func (rq *RepositoryQuerier) QueryTimeseries(ctx context.Context, request CostTi
 				End:         *window.End(),
 				AggregateBy: request.AggregateBy,
 				Filter:      request.Filter,
-				Accumulate:  request.Accumulate,
+				Accumulate:  accumulate,
 			})
 		}(i, w, totals)
 	}
diff --git a/pkg/customcost/repositoryquerier_test.go b/pkg/customcost/repositoryquerier_test.go
index b560f11fd..9c6848903 100644
--- a/pkg/customcost/repositoryquerier_test.go
+++ b/pkg/customcost/repositoryquerier_test.go
@@ -67,7 +67,7 @@ func TestGetCustomCostAccumulateOption(t *testing.T) {
 	}
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {
-			got, err := GetCustomCostAccumulateOption(tt.window, tt.from)
+			got, err := getCustomCostAccumulateOption(tt.window, tt.from)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("GetAccumulateOption() error = %v, wantErr %v", err, tt.wantErr)
 				return