diff --git a/qse/cmd/http/ursd.c b/qse/cmd/http/ursd.c
index 6dbaa3d4..45d58c97 100644
--- a/qse/cmd/http/ursd.c
+++ b/qse/cmd/http/ursd.c
@@ -969,7 +969,7 @@ static int httpd_main (int argc, qse_char_t* argv[])
 	while (!g_stop_requested)
 	{
 		qse_ntime_t tmout;
-		qse_cleartime (&tmout);
+		qse_clear_ntime (&tmout);
 
 		/* if there are pending requests, use timeout of 0.
 		 * this way, multiplexer events and pending requests can be
diff --git a/qse/include/qse/cmn/time.h b/qse/include/qse/cmn/time.h
index 6432c4ea..ae88d410 100644
--- a/qse/include/qse/cmn/time.h
+++ b/qse/include/qse/cmn/time.h
@@ -130,32 +130,32 @@ struct qse_btime_t
 typedef qse_long_t qse_mtime_t;
 
 #if defined(QSE_HAVE_INLINE)
-	static QSE_INLINE void qse_inittime(qse_ntime_t* x, qse_ntime_sec_t s, qse_ntime_nsec_t nsec)
+	static QSE_INLINE void qse_init_ntime(qse_ntime_t* x, qse_ntime_sec_t s, qse_ntime_nsec_t nsec)
 	{
 		x->sec = s;
 		x->nsec = nsec;
 	}
-	static QSE_INLINE void qse_cleartime(qse_ntime_t* x) {	qse_inittime (x, 0, 0); }
-	/*static QSE_INLINE int qse_cmptime(const qse_ntime_t* x, const qse_ntime_t* y)
+	static QSE_INLINE void qse_clear_ntime(qse_ntime_t* x) { qse_init_ntime (x, 0, 0); }
+	/*static QSE_INLINE int qse_cmp_ntime(const qse_ntime_t* x, const qse_ntime_t* y)
 	{
 		// TODO: fix the type and value range issue and replace the macro below.
 		return (x->sec == y->sec)? (x->nsec - y->nsec): (x->sec - y->sec);
 	}*/
-#	define qse_cmptime(x,y) (((x)->sec == (y)->sec)? ((x)->nsec - (y)->nsec): ((x)->sec - (y)->sec))
+#	define qse_cmp_ntime(x,y) (((x)->sec == (y)->sec)? ((x)->nsec - (y)->nsec): ((x)->sec - (y)->sec))
 
-	static QSE_INLINE int qse_isnegtime(qse_ntime_t* x) { return x->sec < 0; }
-	static QSE_INLINE int qse_ispostime(qse_ntime_t* x) { return x->sec > 0 || (x->sec == 0 && x->nsec > 0); }
-	static QSE_INLINE int qse_iszerotime(qse_ntime_t* x) { return x->sec == 0 && x->nsec == 0; }
+	static QSE_INLINE int qse_is_neg_ntime(qse_ntime_t* x) { return x->sec < 0; }
+	static QSE_INLINE int qse_is_pos_ntime(qse_ntime_t* x) { return x->sec > 0 || (x->sec == 0 && x->nsec > 0); }
+	static QSE_INLINE int qse_is_zero_ntime(qse_ntime_t* x) { return x->sec == 0 && x->nsec == 0; }
 #else
-#	define qse_inittime(x,s,ns) (((x)->sec = (s)), ((x)->nsec = (ns)))
-#	define qse_cleartime(x) qse_inittime(x,0,0)
-#	define qse_cmptime(x,y) (((x)->sec == (y)->sec)? ((x)->nsec - (y)->nsec): ((x)->sec - (y)->sec))
+#	define qse_init_ntime(x,s,ns) (((x)->sec = (s)), ((x)->nsec = (ns)))
+#	define qse_clear_ntime(x) qse_init_ntime(x,0,0)
+#	define qse_cmp_ntime(x,y) (((x)->sec == (y)->sec)? ((x)->nsec - (y)->nsec): ((x)->sec - (y)->sec))
 
 /* if time has been normalized properly, nsec must be equal to or
  * greater than 0. */
-#	define qse_isnegtime(x) ((x)->sec < 0)
-#	define qse_ispostime(x) ((x)->sec > 0 || ((x)->sec == 0 && (x)->nsec > 0))
-#	define qse_iszerotime(x) ((x)->sec == 0 && (x)->nsec == 0)
+#	define qse_is_neg_ntime(x) ((x)->sec < 0)
+#	define qse_is_pos_ntime(x) ((x)->sec > 0 || ((x)->sec == 0 && (x)->nsec > 0))
+#	define qse_is_zero_ntime(x) ((x)->sec == 0 && (x)->nsec == 0)
 #endif
 
 
@@ -220,26 +220,26 @@ QSE_EXPORT int qse_timelocal (
 );
 
 /**
- * The qse_addtime() function adds x and y and stores the result in z 
+ * The qse_add_time() function adds x and y and stores the result in z 
  */
-QSE_EXPORT void qse_addtime (
+QSE_EXPORT void qse_add_ntime (
+	qse_ntime_t*       z,
 	const qse_ntime_t* x,
-	const qse_ntime_t* y,
-	qse_ntime_t*       z
+	const qse_ntime_t* y
 );
 
 /**
- * The qse_subtime() function subtract y from x and stores the result in z.
+ * The qse_sub_time() function subtract y from x and stores the result in z.
  */
-QSE_EXPORT void qse_subtime (
+QSE_EXPORT void qse_sub_ntime (
+	qse_ntime_t*       z,
 	const qse_ntime_t* x,
-	const qse_ntime_t* y,
-	qse_ntime_t*       z
+	const qse_ntime_t* y
 );
 
 
 /**
- * The qse_strtontime() function converts a numeric text to the numeric time.
+ * The qse_mbs_to_ntime() function converts a numeric text to the numeric time.
  *  seconds.nanoseconds
  *  10.231
  */
diff --git a/qse/lib/cmn/time.c b/qse/lib/cmn/time.c
index e91a5c0b..d9c78191 100644
--- a/qse/lib/cmn/time.c
+++ b/qse/lib/cmn/time.c
@@ -614,7 +614,7 @@ int qse_timelocal (const qse_btime_t* bt, qse_ntime_t* nt)
 	return 0;
 }
 
-void qse_addtime (const qse_ntime_t* x, const qse_ntime_t* y, qse_ntime_t* z)
+void qse_add_ntime (qse_ntime_t* z, const qse_ntime_t* x, const qse_ntime_t* y)
 {
 	QSE_ASSERT (x->nsec >= 0 && x->nsec < QSE_NSECS_PER_SEC);
 	QSE_ASSERT (y->nsec >= 0 && y->nsec < QSE_NSECS_PER_SEC);
@@ -679,7 +679,7 @@ void qse_addtime (const qse_ntime_t* x, const qse_ntime_t* y, qse_ntime_t* z)
 #endif
 }
 
-void qse_subtime (const qse_ntime_t* x, const qse_ntime_t* y, qse_ntime_t* z)
+void qse_sub_ntime (qse_ntime_t* z, const qse_ntime_t* x, const qse_ntime_t* y)
 {
 	QSE_ASSERT (x->nsec >= 0 && x->nsec < QSE_NSECS_PER_SEC);
 	QSE_ASSERT (y->nsec >= 0 && y->nsec < QSE_NSECS_PER_SEC);
diff --git a/qse/lib/cmn/tmr.c b/qse/lib/cmn/tmr.c
index f6187e63..c56f5335 100644
--- a/qse/lib/cmn/tmr.c
+++ b/qse/lib/cmn/tmr.c
@@ -31,7 +31,7 @@
 #define HEAP_LEFT(x)   ((x) * 2 + 1)
 #define HEAP_RIGHT(x)  ((x) * 2 + 2)
 
-#define YOUNGER_THAN(x,y) (qse_cmptime(&(x)->when, &(y)->when) < 0)
+#define YOUNGER_THAN(x,y) (qse_cmp_ntime(&(x)->when, &(y)->when) < 0)
 
 qse_tmr_t* qse_tmr_open (qse_mmgr_t* mmgr, qse_size_t xtnsize, qse_size_t capa)
 {
@@ -236,11 +236,11 @@ int qse_tmr_fire (qse_tmr_t* tmr, const qse_ntime_t* tm, qse_size_t* firecnt)
 
 	/* if the current time is not specified, get it from the system */
 	if (tm) now = *tm;
-	else if (qse_gettime (&now) <= -1) return -1;
+	else if (qse_gettime(&now) <= -1) return -1;
 
 	while (tmr->size > 0)
 	{
-		if (qse_cmptime(&tmr->event[0].when, &now) > 0) break;
+		if (qse_cmp_ntime(&tmr->event[0].when, &now) > 0) break;
 
 		event = tmr->event[0];
 		qse_tmr_delete (tmr, 0); /* remove the registered event structure */
@@ -262,10 +262,10 @@ int qse_tmr_gettmout (qse_tmr_t* tmr, const qse_ntime_t* tm, qse_ntime_t* tmout)
 
 	/* if the current time is not specified, get it from the system */
 	if (tm) now = *tm;
-	else if (qse_gettime (&now) <= -1) return -1;
+	else if (qse_gettime(&now) <= -1) return -1;
 
-	qse_subtime (&tmr->event[0].when, &now, tmout);
-	if (tmout->sec < 0) qse_cleartime (tmout);
+	qse_sub_ntime (tmout, &tmr->event[0].when, &now);
+	if (qse_is_neg_ntime(tmout)) qse_clear_ntime (tmout);
 
 	return 0;
 }
diff --git a/qse/lib/http/httpd-std-dns.h b/qse/lib/http/httpd-std-dns.h
index abf54d8b..ede3fadb 100644
--- a/qse/lib/http/httpd-std-dns.h
+++ b/qse/lib/http/httpd-std-dns.h
@@ -838,7 +838,7 @@ static void tmr_dns_tmout_handle (qse_tmr_t* tmr, const qse_ntime_t* now, qse_tm
 
 		QSE_MEMSET (&tmout_event, 0, QSE_SIZEOF(tmout_event));
 		qse_gettime (&tmout_event.when);
-		qse_addtime (&tmout_event.when, &req->dns_tmout, &tmout_event.when);
+		qse_add_ntime (&tmout_event.when, &req->dns_tmout, &tmout_event.when);
 		tmout_event.ctx = req;
 		tmout_event.handler = tmr_dns_tmout_handle;
 		tmout_event.updater = tmr_dns_tmout_update;
@@ -1006,7 +1006,7 @@ static int dns_send (qse_httpd_t* httpd, qse_httpd_dns_t* dns, const qse_mchar_t
 
 	QSE_MEMSET (&tmout_event, 0, QSE_SIZEOF(tmout_event));
 	qse_gettime (&tmout_event.when);
-	qse_addtime (&tmout_event.when, &req->dns_tmout, &tmout_event.when);
+	qse_add_ntime (&tmout_event.when, &req->dns_tmout, &tmout_event.when);
 	tmout_event.ctx = req;
 	tmout_event.handler = tmr_dns_tmout_handle;
 	tmout_event.updater = tmr_dns_tmout_update;
diff --git a/qse/lib/http/httpd-std-urs.h b/qse/lib/http/httpd-std-urs.h
index 3635f703..6b47024e 100644
--- a/qse/lib/http/httpd-std-urs.h
+++ b/qse/lib/http/httpd-std-urs.h
@@ -364,7 +364,7 @@ static void tmr_urs_tmout_handle (qse_tmr_t* tmr, const qse_ntime_t* now, qse_tm
 
 		QSE_MEMSET (&tmout_event, 0, QSE_SIZEOF(tmout_event));
 		qse_gettime (&tmout_event.when);
-		qse_addtime (&tmout_event.when, &req->urs_tmout, &tmout_event.when);
+		qse_add_ntime (&tmout_event.when, &req->urs_tmout, &tmout_event.when);
 		tmout_event.ctx = req;
 		tmout_event.handler = tmr_urs_tmout_handle;
 		tmout_event.updater = tmr_urs_tmout_update;
@@ -506,7 +506,7 @@ static int urs_send (qse_httpd_t* httpd, qse_httpd_urs_t* urs, const qse_mchar_t
 
 	QSE_MEMSET (&tmout_event, 0, QSE_SIZEOF(tmout_event));
 	qse_gettime (&tmout_event.when);
-	qse_addtime (&tmout_event.when, &req->urs_tmout, &tmout_event.when);
+	qse_add_ntime (&tmout_event.when, &req->urs_tmout, &tmout_event.when);
 	tmout_event.ctx = req;
 	tmout_event.handler = tmr_urs_tmout_handle;
 	tmout_event.updater = tmr_urs_tmout_update;
diff --git a/qse/lib/http/httpd.c b/qse/lib/http/httpd.c
index 34d61358..62e4c33b 100644
--- a/qse/lib/http/httpd.c
+++ b/qse/lib/http/httpd.c
@@ -558,13 +558,13 @@ qse_httpd_peer_t* qse_httpd_decacheproxypeer (
 	{
 		next = peer->next;
 
-		qse_subtime (&now, &peer->timestamp, &diff);
-		if (qse_cmptime(&diff, &diff_limit) >= 0)
+		qse_sub_ntime (&diff, &now, &peer->timestamp);
+		if (qse_cmp_ntime(&diff, &diff_limit) >= 0)
 		{
 			/* the entry is too old */
 			purge_cached_proxy_peer (httpd, client, peer);
 		}
-		else if (qse_nwadequal (nwad, &peer->nwad) && qse_nwadequal (local, &peer->local))
+		else if (qse_nwadequal(nwad, &peer->nwad) && qse_nwadequal (local, &peer->local))
 		{
 			if ((secure && (peer->flags & QSE_HTTPD_PEER_SECURE)) ||
 			    (!secure && !(peer->flags & QSE_HTTPD_PEER_SECURE))) 
@@ -644,7 +644,7 @@ static qse_httpd_client_t* new_client (qse_httpd_t* httpd, qse_httpd_client_t* t
 		/* idle limit is enabled when the limit is greater than 0.0 */
 		QSE_MEMSET (&idle_event, 0, QSE_SIZEOF(idle_event));
 		qse_gettime (&idle_event.when);
-		qse_addtime (&idle_event.when, &httpd->opt.idle_limit, &idle_event.when);
+		qse_add_ntime (&idle_event.when, &httpd->opt.idle_limit, &idle_event.when);
 		idle_event.ctx = client;
 		idle_event.handler = tmr_idle_handle;
 		idle_event.updater = tmr_idle_update;
@@ -894,11 +894,11 @@ static void tmr_idle_handle (qse_tmr_t* tmr, const qse_ntime_t* now, qse_tmr_eve
 {
 	qse_httpd_client_t* client = (qse_httpd_client_t*)evt->ctx;
 
-	if (qse_cmptime(now, &client->last_active) >= 0)
+	if (qse_cmp_ntime(now, &client->last_active) >= 0)
 	{
 		qse_ntime_t diff;
-		qse_subtime (now, &client->last_active, &diff);
-		if (qse_cmptime(&diff, &client->server->httpd->opt.idle_limit) >= 0)
+		qse_sub_ntime (&diff, now, &client->last_active);
+		if (qse_cmp_ntime(&diff, &client->server->httpd->opt.idle_limit) >= 0)
 		{
 			/* this client is idle */
 			HTTPD_DBGOUT1 ("Purging idle client %zd\n", (qse_size_t)client->handle);
@@ -913,7 +913,7 @@ static void tmr_idle_handle (qse_tmr_t* tmr, const qse_ntime_t* now, qse_tmr_eve
 			/*qse_gettime (&idle_event.when);*/
 			QSE_MEMSET (&idle_event, 0, QSE_SIZEOF(idle_event));
 			idle_event.when = *now;
-			qse_addtime (&idle_event.when, &client->server->httpd->opt.idle_limit, &idle_event.when);
+			qse_add_ntime (&idle_event.when, &client->server->httpd->opt.idle_limit, &idle_event.when);
 			idle_event.ctx = client;
 			idle_event.handler = tmr_idle_handle;
 			idle_event.updater = tmr_idle_update;
diff --git a/qse/lib/si/cnd.c b/qse/lib/si/cnd.c
index e0a461d9..2ee590aa 100644
--- a/qse/lib/si/cnd.c
+++ b/qse/lib/si/cnd.c
@@ -363,7 +363,7 @@ void qse_cnd_wait (qse_cnd_t* cnd, qse_mtx_t* mutex, const qse_ntime_t* waiting_
 		struct timespec ts;
 
 		qse_gettime (&t);
-		qse_addtime (&t, waiting_time, &t);
+		qse_add_ntime (&t, waiting_time, &t);
 
 		ts.tv_sec = t.sec;
 		ts.tv_nsec = t.nsec;
diff --git a/qse/lib/si/mtx.c b/qse/lib/si/mtx.c
index 0c4a9af8..d51d8930 100644
--- a/qse/lib/si/mtx.c
+++ b/qse/lib/si/mtx.c
@@ -220,7 +220,7 @@ int qse_mtx_lock (qse_mtx_t* mtx, const qse_ntime_t* waiting_time)
 		struct timespec ts;
 
 		qse_gettime (&t);
-		qse_addtime (&t, waiting_time, &t);
+		qse_add_ntime (&t, waiting_time, &t);
 
 		ts.tv_sec = t.sec;
 		ts.tv_nsec = t.nsec;
diff --git a/qse/lib/si/rwl.c b/qse/lib/si/rwl.c
index 1e38323f..96286cb1 100644
--- a/qse/lib/si/rwl.c
+++ b/qse/lib/si/rwl.c
@@ -106,9 +106,9 @@ int qse_rwl_lockr (qse_rwl_t* rwl, const qse_ntime_t* waiting_time)
 
 	if (waiting_time)
 	{
-		qse_cleartime (&zero);
+		qse_clear_ntime (&zero);
 		qse_gettime (&now);
-		qse_addtime (&now, waiting_time, &dead_line);
+		qse_add_ntime (&dead_line, &now, waiting_time);
 	}
 	if (qse_mtx_lock (&rwl->mtx, waiting_time) <= -1) return -1;
 
@@ -120,8 +120,8 @@ int qse_rwl_lockr (qse_rwl_t* rwl, const qse_ntime_t* waiting_time)
 			if (waiting_time)
 			{
 				qse_gettime (&now);
-				qse_subtime (&dead_line, &now, &rem);
-				if (qse_cmptime(&rem, &zero) <= 0)
+				qse_sub_ntime (&rem, &dead_line, &now);
+				if (qse_cmp_ntime(&rem, &zero) <= 0)
 				{
 					/* timed out */
 					rwl->rwait_count--;
@@ -170,9 +170,9 @@ int qse_rwl_lockw (qse_rwl_t* rwl, const qse_ntime_t* waiting_time)
 
 	if (waiting_time)
 	{
-		qse_cleartime (&zero);
+		qse_clear_ntime (&zero);
 		qse_gettime (&now);
-		qse_addtime (&now, waiting_time, &dead_line);
+		qse_add_ntime (&dead_line, &now, waiting_time);
 	}
 	if (qse_mtx_lock (&rwl->mtx, waiting_time) <= -1) return -1;
 
@@ -184,8 +184,8 @@ int qse_rwl_lockw (qse_rwl_t* rwl, const qse_ntime_t* waiting_time)
 			if (waiting_time)
 			{
 				qse_gettime (&now);
-				qse_subtime (&dead_line, &now, &rem);
-				if (qse_cmptime(&rem, &zero) <= 0)
+				qse_sub_ntime (&rem, &dead_line, &now);
+				if (qse_cmp_ntime(&rem, &zero) <= 0)
 				{
 					/* timed out */
 					rwl->wwait_count--;
diff --git a/qse/samples/http/httpd01.c b/qse/samples/http/httpd01.c
index b10c688c..544530a9 100644
--- a/qse/samples/http/httpd01.c
+++ b/qse/samples/http/httpd01.c
@@ -84,7 +84,7 @@ static int httpd_main (int argc, qse_char_t* argv[])
 		int trait = QSE_HTTPD_CGIERRTONUL;
 		qse_httpd_setopt (httpd, QSE_HTTPD_TRAIT,  &trait);
 
-		qse_inittime (&tmout, 10, 0);
+		qse_init_ntime (&tmout, 10, 0);
 		qse_httpd_setopt (httpd, QSE_HTTPD_TMOUT,  &tmout);
 	}
 
diff --git a/qse/samples/si/rwl01.c b/qse/samples/si/rwl01.c
index d0ec5155..dee33cb5 100644
--- a/qse/samples/si/rwl01.c
+++ b/qse/samples/si/rwl01.c
@@ -57,7 +57,7 @@ static int thr_exec (qse_thr_t* thr, void* ctx)
 			qse_ntime_t x;
 			OUTMSG (QSE_T("write waiting"), xtn->id);
 
-			qse_inittime (&x, 3, 0);
+			qse_init_ntime (&x, 3, 0);
 			/*if (qse_rwl_lockw (rwl, QSE_NULL) >= 0)*/
 			if (qse_rwl_lockw (rwl, &x) >= 0)
 			{