diff --git a/dguta/dguta_test.go b/dguta/dguta_test.go
index 91082d04..ed713c06 100644
--- a/dguta/dguta_test.go
+++ b/dguta/dguta_test.go
@@ -98,7 +98,8 @@ func TestDGUTA(t *testing.T) {
 		})
 	})
 
-	dgutaData, expectedRootGUTAs, expected, expectedKeys := testData(t)
+	refUnixTime := time.Now().Unix()
+	dgutaData, expectedRootGUTAs, expected, expectedKeys := testData(t, refUnixTime)
 
 	Convey("You can see if a GUTA passes a filter", t, func() {
 		numGutas := 17
@@ -588,10 +589,11 @@ type gutaInfo struct {
 }
 
 // testData provides some test data and expected results.
-func testData(t *testing.T) (dgutaData string, expectedRootGUTAs GUTAs, expected []*DGUTA, expectedKeys []string) {
+func testData(t *testing.T, refUnixTime int64) (dgutaData string, expectedRootGUTAs GUTAs,
+	expected []*DGUTA, expectedKeys []string) {
 	t.Helper()
 
-	dgutaData = internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(1, 2, 1, 101, 102))
+	dgutaData = internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(1, 2, 1, 101, 102, refUnixTime))
 
 	orderOfOldAges := []summary.DirGUTAge{
 		summary.DGUTAgeAll, summary.DGUTAgeA1M, summary.DGUTAgeM2M,
diff --git a/dguta/tree_test.go b/dguta/tree_test.go
index 90087fc4..266681ee 100644
--- a/dguta/tree_test.go
+++ b/dguta/tree_test.go
@@ -41,6 +41,8 @@ import (
 func TestTree(t *testing.T) {
 	expectedFTsBam := []summary.DirGUTAFileType{summary.DGUTAFileTypeBam}
 
+	refUnixTime := time.Now().Unix()
+
 	Convey("You can make a Tree from a dguta database", t, func() {
 		paths, err := testMakeDBPaths(t)
 		So(err, ShouldBeNil)
@@ -49,7 +51,7 @@ func TestTree(t *testing.T) {
 		So(errc, ShouldNotBeNil)
 		So(tree, ShouldBeNil)
 
-		errc = testCreateDB(t, paths[0])
+		errc = testCreateDB(t, paths[0], refUnixTime)
 		So(errc, ShouldBeNil)
 
 		tree, errc = NewTree(paths[0])
@@ -70,7 +72,7 @@ func TestTree(t *testing.T) {
 		expectedFTsCramAndDir := []summary.DirGUTAFileType{summary.DGUTAFileTypeCram, summary.DGUTAFileTypeDir}
 		expectedAtime := time.Unix(50, 0)
 		expectedAtimeG := time.Unix(60, 0)
-		expectedMtime := time.Unix(time.Now().Unix()-(summary.SecondsInAYear*3), 0)
+		expectedMtime := time.Unix(refUnixTime-(summary.SecondsInAYear*3), 0)
 
 		const numDirectories = 10
 
@@ -378,10 +380,10 @@ func TestTree(t *testing.T) {
 	})
 }
 
-func testCreateDB(t *testing.T, path string) error {
+func testCreateDB(t *testing.T, path string, refUnixTime int64) error {
 	t.Helper()
 
-	dgutData := internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(1, 2, 1, 101, 102))
+	dgutData := internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(1, 2, 1, 101, 102, refUnixTime))
 	data := strings.NewReader(dgutData)
 	db := NewDB(path)
 
diff --git a/internal/data/data.go b/internal/data/data.go
index 76d3d453..c7914ef5 100644
--- a/internal/data/data.go
+++ b/internal/data/data.go
@@ -60,7 +60,7 @@ type TestFile struct {
 	ATime, MTime   int
 }
 
-func CreateDefaultTestData(gidA, gidB, gidC, uidA, uidB int) []TestFile {
+func CreateDefaultTestData(gidA, gidB, gidC, uidA, uidB int, refUnixTime int64) []TestFile {
 	dir := "/"
 	abdf := filepath.Join(dir, "a", "b", "d", "f")
 	abdg := filepath.Join(dir, "a", "b", "d", "g")
@@ -126,8 +126,8 @@ func CreateDefaultTestData(gidA, gidB, gidC, uidA, uidB int) []TestFile {
 			SizeOfEachFile: 1,
 			GID:            3,
 			UID:            103,
-			ATime:          int(time.Now().Unix() - summary.SecondsInAYear),
-			MTime:          int(time.Now().Unix() - (summary.SecondsInAYear * 3)),
+			ATime:          int(refUnixTime - summary.SecondsInAYear),
+			MTime:          int(refUnixTime - (summary.SecondsInAYear * 3)),
 		},
 	}
 
diff --git a/internal/db/dguta.go b/internal/db/dguta.go
index 7dc9a628..b52f430d 100644
--- a/internal/db/dguta.go
+++ b/internal/db/dguta.go
@@ -49,7 +49,7 @@ const exampleDBBatchSize = 20
 // CreateExampleDGUTADB creates a temporary dguta.db from some example data that
 // uses your uid and 2 of your gids, and returns the path to the database
 // directory. For use when testing something that needs a Tree.
-func CreateExampleDGUTADB(t *testing.T) (string, error) {
+func CreateExampleDGUTADB(t *testing.T, refUnixTime int64) (string, error) {
 	t.Helper()
 
 	_, uid, gids := GetUserAndGroups(t)
@@ -57,16 +57,16 @@ func CreateExampleDGUTADB(t *testing.T) (string, error) {
 		gids = append(gids, "0")
 	}
 
-	return CreateExampleDGUTADBCustomIDs(t, uid, gids[0], gids[1])
+	return CreateExampleDGUTADBCustomIDs(t, uid, gids[0], gids[1], refUnixTime)
 }
 
 // CreateExampleDGUTADBCustomIDs creates a temporary dguta.db from some example
 // data that uses the given uid and gids, and returns the path to the database
 // directory.
-func CreateExampleDGUTADBCustomIDs(t *testing.T, uid, gidA, gidB string) (string, error) {
+func CreateExampleDGUTADBCustomIDs(t *testing.T, uid, gidA, gidB string, refUnixTime int64) (string, error) {
 	t.Helper()
 
-	dgutaData := exampleDGUTAData(t, uid, gidA, gidB)
+	dgutaData := exampleDGUTAData(t, uid, gidA, gidB, refUnixTime)
 
 	return CreateCustomDGUTADB(t, dgutaData)
 }
@@ -103,7 +103,7 @@ func createExampleDgutaDir(t *testing.T) (string, error) {
 
 // exampleDGUTAData is some example DGUTA data that uses the given uid and gids,
 // along with root's uid.
-func exampleDGUTAData(t *testing.T, uidStr, gidAStr, gidBStr string) string {
+func exampleDGUTAData(t *testing.T, uidStr, gidAStr, gidBStr string, refUnixTime int64) string {
 	t.Helper()
 
 	uid, err := strconv.ParseUint(uidStr, 10, 64)
@@ -121,7 +121,7 @@ func exampleDGUTAData(t *testing.T, uidStr, gidAStr, gidBStr string) string {
 		t.Fatal(err)
 	}
 
-	return internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(int(gidA), int(gidB), 0, int(uid), 0))
+	return internaldata.TestDGUTAData(t, internaldata.CreateDefaultTestData(int(gidA), int(gidB), 0, int(uid), 0, refUnixTime))
 }
 
 func CreateDGUTADBFromFakeFiles(t *testing.T, files []internaldata.TestFile,