diff --git a/devicemodel/hw/platform/hpet.c b/devicemodel/hw/platform/hpet.c
index 72f4bac13..9d465a37c 100644
--- a/devicemodel/hw/platform/hpet.c
+++ b/devicemodel/hw/platform/hpet.c
@@ -202,7 +202,7 @@ vhpet_counter(struct vhpet *vhpet, struct timespec *nowptr)
 	val = vhpet->countbase;
 
 	if (vhpet_counter_enabled(vhpet)) {
-		if (clock_gettime(CLOCK_REALTIME, &now))
+		if (clock_gettime(CLOCK_MONOTONIC, &now))
 			pr_dbg("clock_gettime returned: %s", strerror(errno));
 
 		/* delta = now - countbase_ts */
@@ -225,7 +225,7 @@ vhpet_counter(struct vhpet *vhpet, struct timespec *nowptr)
 		 */
 		if (nowptr) {
 			pr_warn("vhpet unexpected nowptr");
-			if (clock_gettime(CLOCK_REALTIME, nowptr))
+			if (clock_gettime(CLOCK_MONOTONIC, nowptr))
 				pr_dbg("clock_gettime returned: %s", strerror(errno));
 		}
 	}
@@ -366,7 +366,7 @@ vhpet_timer_handler(void *a, uint64_t nexp)
 
 	vhpet_timer_interrupt(vhpet, n);
 
-	if (clock_gettime(CLOCK_REALTIME, &now))
+	if (clock_gettime(CLOCK_MONOTONIC, &now))
 		pr_dbg("clock_gettime returned: %s", strerror(errno));
 
 	if (acrn_timer_gettime(vhpet_tmr(vhpet, n), &tmrts))
@@ -548,7 +548,7 @@ vhpet_start_counting(struct vhpet *vhpet)
 {
 	int i;
 
-	if (clock_gettime(CLOCK_REALTIME, &vhpet->countbase_ts))
+	if (clock_gettime(CLOCK_MONOTONIC, &vhpet->countbase_ts))
 		pr_dbg("clock_gettime returned: %s", strerror(errno));
 
 	/* Restart the timers based on the main counter base value */
@@ -639,7 +639,7 @@ vhpet_timer_update_config(struct vhpet *vhpet, int n, uint64_t data,
 			 *   - Timer remains in periodic mode
 			 */
 			if (!vhpet_timer_enabled(vhpet, n)) {
-				if (clock_gettime(CLOCK_REALTIME, &now))
+				if (clock_gettime(CLOCK_MONOTONIC, &now))
 					pr_dbg("clock_gettime returned: %s", strerror(errno));
 				vhpet_stop_timer(vhpet, n, &now, true);
 			} else if (!(oldval & (HPET_TCNF_TYPE | HPET_TCNF_INT_ENB)) ||
@@ -998,7 +998,7 @@ vhpet_init(struct vmctx *ctx)
 			arg->timer_num = i;
 
 			tmr = &vhpet->timer[i].tmrlst[j].t;
-			tmr->clockid = CLOCK_REALTIME;
+			tmr->clockid = CLOCK_MONOTONIC;
 			error = acrn_timer_init(tmr, vhpet_timer_handler, arg);
 
 			if (error) {
diff --git a/devicemodel/hw/platform/pit.c b/devicemodel/hw/platform/pit.c
index f673f4734..a3695e842 100644
--- a/devicemodel/hw/platform/pit.c
+++ b/devicemodel/hw/platform/pit.c
@@ -107,7 +107,7 @@ ticks_elapsed_since(const struct timespec *since)
 {
 	struct timespec ts;
 
-	if (clock_gettime(CLOCK_REALTIME, &ts))
+	if (clock_gettime(CLOCK_MONOTONIC, &ts))
 		pr_dbg("clock_gettime returned: %s", strerror(errno));
 
 	if (timespeccmp(&ts, since, <=))
@@ -192,7 +192,7 @@ pit_load_ce(struct channel *c)
 		c->nullcnt = false;
 		c->crbyte = 0;
 
-		if (clock_gettime(CLOCK_REALTIME, &c->start_ts))
+		if (clock_gettime(CLOCK_MONOTONIC, &c->start_ts))
 			pr_dbg("clock_gettime returned: %s", strerror(errno));
 
 		if (c->initial == 0 || c->initial > 0x10000) {
@@ -330,7 +330,7 @@ pit_timer_start_cntr0(struct vpit *vpit)
 	sigevt.sigev_notify = SIGEV_THREAD;
 	sigevt.sigev_notify_function = vpit_timer_handler;
 
-	if (timer_create(CLOCK_REALTIME, &sigevt, &c->timer_id))
+	if (timer_create(CLOCK_MONOTONIC, &sigevt, &c->timer_id))
 		pr_dbg("timer_create returned: %s", strerror(errno));
 
 	vpit_timer_arg[c->timer_idx].active = true;
@@ -360,7 +360,7 @@ pit_update_counter(struct vpit *vpit, struct channel *c, bool latch,
 
 		c->initial = PIT_HZ_TO_TICKS(100);
 		delta_ticks = 0;
-		if (clock_gettime(CLOCK_REALTIME, &c->start_ts))
+		if (clock_gettime(CLOCK_MONOTONIC, &c->start_ts))
 			pr_dbg("clock_gettime returned: %s", strerror(errno));
 	} else
 		delta_ticks = ticks_elapsed_since(&c->start_ts);
diff --git a/devicemodel/hw/platform/rtc.c b/devicemodel/hw/platform/rtc.c
index 82de9b7fb..3ca75a7e5 100644
--- a/devicemodel/hw/platform/rtc.c
+++ b/devicemodel/hw/platform/rtc.c
@@ -1148,11 +1148,11 @@ vrtc_init(struct vmctx *ctx)
 	pthread_mutex_unlock(&vrtc->mtx);
 
 	/* init periodic interrupt timer */
-	vrtc->periodic_timer.clockid = CLOCK_REALTIME;
+	vrtc->periodic_timer.clockid = CLOCK_MONOTONIC;
 	acrn_timer_init(&vrtc->periodic_timer, vrtc_periodic_timer, vrtc);
 
 	/* init update interrupt timer(1s)*/
-	vrtc->update_timer.clockid = CLOCK_REALTIME;
+	vrtc->update_timer.clockid = CLOCK_MONOTONIC;
 	acrn_timer_init(&vrtc->update_timer, vrtc_update_timer, vrtc);
 	vrtc_start_timer(&vrtc->update_timer, 1, 0);