diff --git a/doc/helianthus-doc-ru.odt b/doc/helianthus-doc-ru.odt
index 62893e6..424cc17 100644
Binary files a/doc/helianthus-doc-ru.odt and b/doc/helianthus-doc-ru.odt differ
diff --git a/src/window.c b/src/window.c
index 77639a9..ff3155c 100644
--- a/src/window.c
+++ b/src/window.c
@@ -20,6 +20,9 @@ static unsigned long long elapsedTimeUs;
 static unsigned long long elapsedTimeSinceLastFrameUs;
 static unsigned int prevFrameTimeMs;
 
+static unsigned long long monotonicMs;
+static unsigned int prevMonotonicMs;
+
 HeliDialog dialog;
 
 static Callback initCallback;
@@ -292,6 +295,16 @@ int windowGetFrameCount()
 double windowGetSeconds()
 	{ return started ? elapsedTimeUs*1e-6 : 0.0; }
 
+unsigned long long windowGetMonotonicMilliseconds() {
+	unsigned int ms = SDL_GetTicks();
+	monotonicMs += ms - prevMonotonicMs;
+	prevMonotonicMs = ms;
+	return monotonicMs;
+}
+
+double windowGetMonotonicSeconds()
+	{ return started ? monotonicMs*1e-3 : 0.0; }
+
 void windowSetInit(Callback init)
 	{ initCallback = init; }
 void windowSetDraw(Callback draw)
@@ -436,6 +449,9 @@ static void draw() {
 
 
 static void deinit() {
+	monotonicMs = 0;
+	prevMonotonicMs = 0;
+	
 	heliGLStencilOpSeparatePtr = NULL;
 	
 	if (context) SDL_GL_DeleteContext(context);
@@ -518,6 +534,9 @@ static int init() {
 	glGetIntegerv(GL_READ_FRAMEBUFFER_BINDING, (int*)&heliGLWindowFramebufferReadId);
 	glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (int*)&heliGLWindowFramebufferDrawId);
 	
+	monotonicMs = 0;
+	prevMonotonicMs = SDL_GetTicks();
+	
 	return TRUE;
 }
 
diff --git a/src/window.h b/src/window.h
index c6baaa6..5dd029e 100644
--- a/src/window.h
+++ b/src/window.h
@@ -67,6 +67,8 @@ double windowGetFrameTime();
 
 int windowGetFrameCount();
 double windowGetSeconds();
+double windowGetMonotonicSeconds();
+unsigned long long windowGetMonotonicMilliseconds();
 
 void windowSetInit(Callback init);
 void windowSetDraw(Callback draw);