diff --git a/bin/arm/go-raspberry-pi-timelapse b/bin/arm/go-raspberry-pi-timelapse
index 13cdd13..87b873b 100755
Binary files a/bin/arm/go-raspberry-pi-timelapse and b/bin/arm/go-raspberry-pi-timelapse differ
diff --git a/timelapse/camera.go b/timelapse/camera.go
index 39db41a..6d2fd8d 100644
--- a/timelapse/camera.go
+++ b/timelapse/camera.go
@@ -4,6 +4,7 @@ package timelapse
 
 import (
 	"errors"
+	"fmt"
 	"log"
 	"os/exec"
 	"path/filepath"
@@ -12,7 +13,6 @@ import (
 )
 
 const (
-	timeStampFormat   = "2006-01-02_15:04:05"
 	commandRaspistill = "raspistill"
 )
 
@@ -73,7 +73,10 @@ func (c *Camera) getRaspistillArgs(fullPath string) []string {
 	return append(args, "-o", fullPath)
 }
 
+func getFileName(t time.Time) string {
+	return fmt.Sprintf("%4d%02d%02d-%02d%02d%02d.jpg", t.Year(), t.Month(), t.Day(), t.Hour(), t.Minute(), t.Second())
+}
+
 func (c *Camera) getAbsoluteFilepath() string {
-	fileName := time.Now().Format(timeStampFormat) + ".jpg"
-	return filepath.Join(c.savePath, fileName)
+	return filepath.Join(c.savePath, getFileName(time.Now()))
 }
diff --git a/timelapse/camera_test.go b/timelapse/camera_test.go
index ff0d304..fb0f22d 100644
--- a/timelapse/camera_test.go
+++ b/timelapse/camera_test.go
@@ -3,6 +3,7 @@ package timelapse
 import (
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/facebookgo/ensure"
 )
@@ -20,9 +21,9 @@ func TestBuildingArguments(t *testing.T) {
 	ensure.False(t, unrotatedCamera.flipHorizontally)
 
 	p := unrotatedCamera.getAbsoluteFilepath()
+	// Example: "foo/20210913-184442.jpg"
 	ensure.DeepEqual(t, 0, strings.Index(p, "foo/"))
-	ensure.DeepEqual(t, 23, strings.Index(p, ".jpg"))
-	ensure.DeepEqual(t, 27, len(p))
+	ensure.DeepEqual(t, strings.Index(p, ".jpg"), 19)
 }
 
 func TestRaspistillArgs(t *testing.T) {
@@ -32,7 +33,15 @@ func TestRaspistillArgs(t *testing.T) {
 }
 
 func TestCreateRotatedCamera(t *testing.T) {
-	rotatedCamera, _ := NewCamera("foo", 200, 100, true, 100)
+	rotatedCamera, err := NewCamera("foo", 200, 100, true, 100)
+	ensure.Nil(t, err)
 	ensure.True(t, rotatedCamera.flipVertically)
 	ensure.True(t, rotatedCamera.flipHorizontally)
 }
+
+func TestCreateFileName(t *testing.T) {
+	ensure.DeepEqual(t, getFileName(time.Date(1974, time.January, 1, 1, 0, 0, 0, time.UTC)), "19740101-010000.jpg")
+	ensure.DeepEqual(t, getFileName(time.Date(1974, time.January, 19, 1, 2, 3, 0, time.UTC)), "19740119-010203.jpg")
+	ensure.DeepEqual(t, getFileName(time.Date(1974, time.May, 19, 1, 2, 3, 0, time.UTC)), "19740519-010203.jpg")
+	ensure.DeepEqual(t, getFileName(time.Date(1974, time.December, 19, 1, 2, 3, 4, time.UTC)), "19741219-010203.jpg")
+}