diff --git a/internal/report/report.go b/internal/report/report.go
index d866fad..6116851 100644
--- a/internal/report/report.go
+++ b/internal/report/report.go
@@ -129,29 +129,27 @@ func getReportTime(path string) (int64, error) {
 }
 
 // GetPeriodStart returns the start of the period window for a given period in seconds.
-func GetPeriodStart(period int) (int64, error) {
+func GetPeriodStart(period int, t time.Time) (int64, error) {
 	if period <= 0 {
 		return 0, ErrInvalidPeriod
 	}
-	utcTime := time.Now().UTC().Unix()
-	return utcTime - (utcTime % int64(period)), nil
+	return t.Unix() - (t.Unix() % int64(period)), nil
 }
 
 // GetForPeriod returns the most recent report within a period window for a given directory.
 // Not inclusive of the period end (periodStart + period).
 //
 // For example, given reports 1 and 7, with time 2 and period 7, the function will return the path for report 1.
-func GetForPeriod(dir string, time time.Time, period int) (Report, error) {
-	if period <= 0 {
-		return Report{}, ErrInvalidPeriod
+func GetForPeriod(dir string, t time.Time, period int) (Report, error) {
+	periodStart, err := GetPeriodStart(period, t)
+	if err != nil {
+		return Report{}, err
 	}
-
-	periodStart := time.Unix() - (time.Unix() % int64(period))
 	periodEnd := periodStart + int64(period)
 
 	// Reports names are utc timestamps. Get the most recent report within the period window.
 	var report Report
-	err := filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
+	err = filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
 		if err != nil {
 			return fmt.Errorf("failed to access path: %v", err)
 		}
diff --git a/internal/report/report_test.go b/internal/report/report_test.go
index b41803e..0764e69 100644
--- a/internal/report/report_test.go
+++ b/internal/report/report_test.go
@@ -17,10 +17,13 @@ func TestGetPeriodStart(t *testing.T) {
 
 	tests := map[string]struct {
 		period int
+		time   int64
 
 		wantErr error
 	}{
-		"Valid Period": {period: 500},
+		"Valid Period":      {period: 500, time: 100000},
+		"Negative Time:":    {period: 500, time: -100000},
+		"Non-Multiple Time": {period: 500, time: 1051},
 
 		"Invalid Negative Period": {period: -500, wantErr: report.ErrInvalidPeriod},
 		"Invalid Zero Period":     {period: 0, wantErr: report.ErrInvalidPeriod},
@@ -30,7 +33,7 @@ func TestGetPeriodStart(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 
-			got, err := report.GetPeriodStart(tc.period)
+			got, err := report.GetPeriodStart(tc.period, time.Unix(tc.time, 0))
 			if tc.wantErr != nil {
 				require.ErrorIs(t, err, tc.wantErr)
 				return
@@ -38,6 +41,8 @@ func TestGetPeriodStart(t *testing.T) {
 			require.NoError(t, err, "got an unexpected error")
 
 			require.IsType(t, int64(0), got)
+			want := testutils.LoadWithUpdateFromGoldenYAML(t, got)
+			require.Equal(t, want, got, "GetPeriodStart should return the expect start of the period window")
 		})
 	}
 }
@@ -233,7 +238,7 @@ func TestGetAll(t *testing.T) {
 			}
 			require.NoError(t, err, "got an unexpected error")
 
-			got := make([]report.Report, len(reports))
+			got := make([]report.Report, 0, len(reports))
 			for _, r := range reports {
 				got = append(got, sanitizeReportPath(t, r, dir))
 			}
diff --git a/internal/report/testdata/TestGetAll/golden/files_in_subdir b/internal/report/testdata/TestGetAll/golden/files_in_subdir
index ccc5761..a079365 100644
--- a/internal/report/testdata/TestGetAll/golden/files_in_subdir
+++ b/internal/report/testdata/TestGetAll/golden/files_in_subdir
@@ -1,9 +1,3 @@
-- path: ""
-  name: ""
-  timestamp: 0
-- path: ""
-  name: ""
-  timestamp: 0
 - path: 1.json
   name: 1.json
   timestamp: 1
diff --git a/internal/report/testdata/TestGetAll/golden/mix_of_valid_and_invalid b/internal/report/testdata/TestGetAll/golden/mix_of_valid_and_invalid
index e2ad51f..cd1e267 100644
--- a/internal/report/testdata/TestGetAll/golden/mix_of_valid_and_invalid
+++ b/internal/report/testdata/TestGetAll/golden/mix_of_valid_and_invalid
@@ -1,12 +1,3 @@
-- path: ""
-  name: ""
-  timestamp: 0
-- path: ""
-  name: ""
-  timestamp: 0
-- path: ""
-  name: ""
-  timestamp: 0
 - path: 1.json
   name: 1.json
   timestamp: 1
diff --git a/internal/report/testdata/TestGetPeriodStart/golden/negative_time b/internal/report/testdata/TestGetPeriodStart/golden/negative_time
new file mode 100644
index 0000000..c6730fa
--- /dev/null
+++ b/internal/report/testdata/TestGetPeriodStart/golden/negative_time
@@ -0,0 +1 @@
+-100000
diff --git a/internal/report/testdata/TestGetPeriodStart/golden/non-multiple_time b/internal/report/testdata/TestGetPeriodStart/golden/non-multiple_time
new file mode 100644
index 0000000..83b33d2
--- /dev/null
+++ b/internal/report/testdata/TestGetPeriodStart/golden/non-multiple_time
@@ -0,0 +1 @@
+1000
diff --git a/internal/report/testdata/TestGetPeriodStart/golden/valid_period b/internal/report/testdata/TestGetPeriodStart/golden/valid_period
new file mode 100644
index 0000000..f7393e8
--- /dev/null
+++ b/internal/report/testdata/TestGetPeriodStart/golden/valid_period
@@ -0,0 +1 @@
+100000