diff --git a/services/misc.go b/services/misc.go
index 7f178b7..bb7fb24 100644
--- a/services/misc.go
+++ b/services/misc.go
@@ -5,6 +5,7 @@ import (
 	"github.com/muety/artifex"
 	"github.com/muety/wakapi/config"
 	"github.com/muety/wakapi/utils"
+	"go.uber.org/atomic"
 	"strconv"
 	"sync"
 	"time"
@@ -12,6 +13,12 @@ import (
 	"github.com/muety/wakapi/models"
 )
 
+const (
+	countUsersEvery = 1 * time.Hour
+)
+
+var countLock = sync.Mutex{}
+
 type MiscService struct {
 	config          *config.Config
 	userService     IUserService
@@ -34,25 +41,31 @@ func NewMiscService(userService IUserService, summaryService ISummaryService, ke
 
 func (srv *MiscService) ScheduleCountTotalTime() {
 	logbuch.Info("scheduling total time counting")
-	if _, err := srv.queueDefault.DispatchEvery(srv.CountTotalTime, 1*time.Hour); err != nil {
+	if _, err := srv.queueDefault.DispatchEvery(srv.CountTotalTime, countUsersEvery); err != nil {
 		config.Log().Error("failed to schedule user counting jobs, %v", err)
 	}
 }
 
 func (srv *MiscService) CountTotalTime() {
+	logbuch.Info("counting users total time")
+	if ok := countLock.TryLock(); !ok {
+		config.Log().Warn("couldn't acquire lock for counting users total time, job is still pending")
+	}
+	defer countLock.Unlock()
+
 	users, err := srv.userService.GetAll()
 	if err != nil {
 		config.Log().Error("failed to fetch users for time counting, %v", err)
 	}
 
-	var totalTime time.Duration = 0
+	var totalTime = atomic.NewDuration(0)
 	var pendingJobs sync.WaitGroup
 	pendingJobs.Add(len(users))
 
 	for _, u := range users {
 		if err := srv.queueWorkers.Dispatch(func() {
 			defer pendingJobs.Done()
-			totalTime += srv.countUserTotalTime(u.ID)
+			totalTime.Add(srv.countUserTotalTime(u.ID))
 		}); err != nil {
 			config.Log().Error("failed to enqueue counting job for user '%s'", u.ID)
 			pendingJobs.Done()
@@ -61,10 +74,10 @@ func (srv *MiscService) CountTotalTime() {
 
 	// persist
 	go func(wg *sync.WaitGroup) {
-		if utils.WaitTimeout(&pendingJobs, 10*time.Minute) {
+		if !utils.WaitTimeout(&pendingJobs, 2*countUsersEvery) {
 			if err := srv.keyValueService.PutString(&models.KeyStringValue{
 				Key:   config.KeyLatestTotalTime,
-				Value: totalTime.String(),
+				Value: totalTime.Load().String(),
 			}); err != nil {
 				config.Log().Error("failed to save total time count: %v", err)
 			}
diff --git a/services/services.go b/services/services.go
index cbee61a..d3db4ed 100644
--- a/services/services.go
+++ b/services/services.go
@@ -13,6 +13,7 @@ type IAggregationService interface {
 
 type IMiscService interface {
 	ScheduleCountTotalTime()
+	CountTotalTime()
 }
 
 type IAliasService interface {