diff --git a/source/eventcore/drivers/posix/driver.d b/source/eventcore/drivers/posix/driver.d
index 0681464..45e0184 100644
--- a/source/eventcore/drivers/posix/driver.d
+++ b/source/eventcore/drivers/posix/driver.d
@@ -19,6 +19,7 @@ import eventcore.drivers.threadedfile;
 import eventcore.internal.consumablequeue : ConsumableQueue;
 import eventcore.internal.utils;
 
+import core.time : MonoTime;
 import std.algorithm.comparison : among, min, max;
 
 version (Posix) {
@@ -221,17 +222,17 @@ final class PosixEventDriverCore(Loop : PosixEventLoop, Timers : EventDriverTime
 
 		if (timeout <= 0.seconds) {
 			got_events = m_loop.doProcessEvents(0.seconds);
-			m_timers.process(currStdTime);
+			m_timers.process(MonoTime.currTime);
 		} else {
-			long now = currStdTime;
+			auto now = MonoTime.currTime;
 			do {
 				auto nextto = max(min(m_timers.getNextTimeout(now), timeout), 0.seconds);
 				got_events = m_loop.doProcessEvents(nextto);
-				long prev_step = now;
-				now = currStdTime;
+				auto prev_step = now;
+				now = MonoTime.currTime;
 				got_events |= m_timers.process(now);
 				if (timeout != Duration.max)
-					timeout -= (now - prev_step).hnsecs;
+					timeout -= now - prev_step;
 			} while (timeout > 0.seconds && !m_exit && !got_events);
 		}
 
diff --git a/source/eventcore/drivers/timer.d b/source/eventcore/drivers/timer.d
index 802b12c..14080cc 100644
--- a/source/eventcore/drivers/timer.d
+++ b/source/eventcore/drivers/timer.d
@@ -7,7 +7,7 @@ import eventcore.driver;
 import eventcore.internal.consumablequeue;
 import eventcore.internal.dlist;
 import eventcore.internal.utils : mallocT, freeT, nogc_assert;
-
+import core.time : Duration, MonoTime, hnsecs;
 
 final class LoopTimeoutTimerDriver : EventDriverTimers {
 	import std.experimental.allocator.building_blocks.free_list;
@@ -17,7 +17,6 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 	import std.container.array;
 	import std.datetime : Clock;
 	import std.range : SortedRange, assumeSorted, take;
-	import core.time : hnsecs, Duration;
 	import core.memory : GC;
 
 	private {
@@ -46,24 +45,22 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 
 	package @property size_t pendingCount() const @safe nothrow { return m_timerQueue.length; }
 
-	final package Duration getNextTimeout(long stdtime)
+	final package Duration getNextTimeout(MonoTime time)
 	@safe nothrow {
 		if (m_timerQueue.empty) return Duration.max;
-		return (m_timerQueue.front.timeout - stdtime).hnsecs;
+		return m_timerQueue.front.timeout - time;
 	}
 
-	final package bool process(long stdtime)
+	final package bool process(MonoTime time)
 	@trusted nothrow {
 		assert(m_firedTimers.length == 0);
 		if (m_timerQueue.empty) return false;
 
-		TimerSlot ts = void;
-		ts.timeout = stdtime+1;
 		foreach (tm; m_timerQueue[]) {
-			if (tm.timeout > stdtime) break;
-			if (tm.repeatDuration > 0) {
+			if (tm.timeout > time) break;
+			if (tm.repeatDuration > Duration.zero) {
 				do tm.timeout += tm.repeatDuration;
-				while (tm.timeout <= stdtime);
+				while (tm.timeout <= time);
 			} else tm.pending = false;
 			m_firedTimers.put(tm);
 		}
@@ -72,7 +69,7 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 
 		foreach (tm; processed_timers) {
 			m_timerQueue.remove(tm);
-			if (tm.repeatDuration > 0)
+			if (tm.repeatDuration > Duration.zero)
 				enqueueTimer(tm);
 		}
 
@@ -98,7 +95,7 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 		GC.addRange(tm, TimerSlot.sizeof, typeid(TimerSlot));
 		tm.id = id;
 		tm.refCount = 1;
-		tm.timeout = long.max;
+		tm.timeout = MonoTime.max;
 		m_timers[id] = tm;
 		return id;
 	}
@@ -108,8 +105,8 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 		scope (failure) assert(false);
 		auto tm = m_timers[timer];
 		if (tm.pending) stop(timer);
-		tm.timeout = Clock.currStdTime + timeout.total!"hnsecs";
-		tm.repeatDuration = repeat.total!"hnsecs";
+		tm.timeout = MonoTime.currTime + timeout;
+		tm.repeatDuration = repeat;
 		tm.pending = true;
 		enqueueTimer(tm);
 	}
@@ -137,7 +134,7 @@ final class LoopTimeoutTimerDriver : EventDriverTimers {
 
 	final override bool isPeriodic(TimerID descriptor)
 	{
-		return m_timers[descriptor].repeatDuration > 0;
+		return m_timers[descriptor].repeatDuration > Duration.zero;
 	}
 
 	final override void wait(TimerID timer, TimerCallback2 callback)
@@ -239,8 +236,8 @@ struct TimerSlot {
 	TimerID id;
 	uint refCount;
 	bool pending;
-	long timeout; // stdtime
-	long repeatDuration;
+	MonoTime timeout;
+	Duration repeatDuration;
 	TimerCallback2 callback; // TODO: use a list with small-value optimization
 
 	DataInitializer userDataDestructor;
diff --git a/source/eventcore/drivers/winapi/core.d b/source/eventcore/drivers/winapi/core.d
index 6fcca7a..fb41e93 100644
--- a/source/eventcore/drivers/winapi/core.d
+++ b/source/eventcore/drivers/winapi/core.d
@@ -96,7 +96,7 @@ final class WinAPIEventDriverCore : EventDriverCore {
 	override ExitReason processEvents(Duration timeout = Duration.max)
 	{
 		import std.algorithm : min;
-		import core.time : hnsecs, seconds;
+		import core.time : MonoTime, seconds;
 
 		if (m_exit) {
 			m_exit = false;
@@ -106,12 +106,12 @@ final class WinAPIEventDriverCore : EventDriverCore {
 		if (!waiterCount) return ExitReason.outOfWaiters;
 
 		bool got_event;
-		long now = currStdTime;
+		auto now = MonoTime.currTime;
 		do {
 			auto nextto = min(m_timers.getNextTimeout(now), timeout);
 			got_event |= doProcessEvents(nextto);
-			long prev_step = now;
-			now = currStdTime;
+			auto prev_step = now;
+			now = MonoTime.currTime;
 			got_event |= m_timers.process(now);
 
 			if (m_exit) {
@@ -119,7 +119,7 @@ final class WinAPIEventDriverCore : EventDriverCore {
 				return ExitReason.exited;
 			} else if (got_event) break;
 			if (timeout != Duration.max)
-				timeout -= (now - prev_step).hnsecs;
+				timeout -= now - prev_step;
 		} while (timeout > 0.seconds);
 
 		if (!waiterCount) return ExitReason.outOfWaiters;