diff --git a/sched/clock/clock_gettime.c b/sched/clock/clock_gettime.c
index 824fa73fc5..f2e05efcdc 100644
--- a/sched/clock/clock_gettime.c
+++ b/sched/clock/clock_gettime.c
@@ -60,7 +60,6 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
 {
 #ifndef CONFIG_CLOCK_TIMEKEEPING
   struct timespec ts;
-  uint32_t carry;
 #endif
   int ret = OK;
 
@@ -120,25 +119,8 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
            */
 
           flags = spin_lock_irqsave(NULL);
-
-          ts.tv_sec  += g_basetime.tv_sec;
-          ts.tv_nsec += g_basetime.tv_nsec;
-
+          clock_timespec_add(&g_basetime, &ts, tp);
           spin_unlock_irqrestore(NULL, flags);
-
-          /* Handle carry to seconds. */
-
-          if (ts.tv_nsec >= NSEC_PER_SEC)
-            {
-              carry       = ts.tv_nsec / NSEC_PER_SEC;
-              ts.tv_sec  += carry;
-              ts.tv_nsec -= (carry * NSEC_PER_SEC);
-            }
-
-          /* And return the result to the caller. */
-
-          tp->tv_sec  = ts.tv_sec;
-          tp->tv_nsec = ts.tv_nsec;
         }
 #endif /* CONFIG_CLOCK_TIMEKEEPING */
     }
diff --git a/sched/clock/clock_initialize.c b/sched/clock/clock_initialize.c
index 8d53f233dc..f61e9b783a 100644
--- a/sched/clock/clock_initialize.c
+++ b/sched/clock/clock_initialize.c
@@ -309,7 +309,6 @@ void clock_resynchronize(FAR struct timespec *rtc_diff)
   struct timespec curr_ts;
   struct timespec rtc_diff_tmp;
   irqstate_t flags;
-  int32_t carry;
   int ret;
 
   if (rtc_diff == NULL)
@@ -346,17 +345,7 @@ void clock_resynchronize(FAR struct timespec *rtc_diff)
    * was last set, this gives us the current time.
    */
 
-  curr_ts.tv_sec  = bias.tv_sec + g_basetime.tv_sec;
-  curr_ts.tv_nsec = bias.tv_nsec + g_basetime.tv_nsec;
-
-  /* Handle carry to seconds. */
-
-  if (curr_ts.tv_nsec >= NSEC_PER_SEC)
-    {
-      carry            = curr_ts.tv_nsec / NSEC_PER_SEC;
-      curr_ts.tv_sec  += carry;
-      curr_ts.tv_nsec -= (carry * NSEC_PER_SEC);
-    }
+  clock_timespec_add(&bias, &g_basetime, &curr_ts);
 
   /* Check if RTC has advanced past system time. */
 
@@ -377,29 +366,7 @@ void clock_resynchronize(FAR struct timespec *rtc_diff)
     {
       /* Output difference between time at entry and new current time. */
 
-      rtc_diff->tv_sec  = rtc_time.tv_sec  - curr_ts.tv_sec;
-      rtc_diff->tv_nsec = rtc_time.tv_nsec - curr_ts.tv_nsec;
-
-      /* Handle carry to seconds. */
-
-      if (rtc_diff->tv_nsec < 0)
-        {
-          carry = -((-(rtc_diff->tv_nsec + 1)) / NSEC_PER_SEC + 1);
-        }
-      else if (rtc_diff->tv_nsec >= NSEC_PER_SEC)
-        {
-          carry = rtc_diff->tv_nsec / NSEC_PER_SEC;
-        }
-      else
-        {
-          carry = 0;
-        }
-
-      if (carry != 0)
-        {
-          rtc_diff->tv_sec  += carry;
-          rtc_diff->tv_nsec -= (carry * NSEC_PER_SEC);
-        }
+      clock_timespec_subtract(&rtc_time, &curr_ts, rtc_diff);
 
       /* Add the sleep time to correct system timer */