diff --git a/mapper/src/App.js b/mapper/src/App.js
index 300b414..59132f4 100644
--- a/mapper/src/App.js
+++ b/mapper/src/App.js
@@ -22,6 +22,22 @@ const durations = [
 	{id: 3, len: 'Year', win: '2h', full: '2 hour', delta: [1, 'years'], format: 'M/D', num: 4380, secs: 7200},
 ];
 
+const parseSlider = (end, duration, slider) => {
+	//console.log(slider);
+	// good luck remembering how this works
+	const lowOffset = slider[0] * duration.secs - duration.num * duration.secs;
+	const highOffset = slider[1] * duration.secs - duration.num * duration.secs;
+
+	const low = moment.unix(end.unix() + lowOffset);
+	const high = moment.unix(end.unix() + highOffset);
+
+	const lowStr = low.utc().format('YYYY-MM-DDTHH:mm:ss[Z]');
+	const highStr = high.utc().format('YYYY-MM-DDTHH:mm:ss[Z]');
+
+	//console.log(lowStr, highStr);
+	return [lowStr, highStr];
+};
+
 function useSensor(measurement, name, end, duration) {
 	const [data, setData] = useState(false);
 	const [loading, setLoading] = useState(false);
@@ -51,9 +67,11 @@ function useSensor(measurement, name, end, duration) {
 
 
 
-function Owntracks({end, duration, range}) {
+function Owntracks({end, duration, slider}) {
 	const [data, loading] = useSensor('owntracks', 'OwnTracks', end, duration);
 
+	const range = parseSlider(end, duration, slider);
+
 	const coords = data.length ? data.filter(x => !range || (x.time >= range[0] && x.time <= range[1])).map(({ lat, lon }) => [lat, lon]).filter(([lat, lon]) => lat !== null || lon !== null) : [];
 
 	const handleSubmit = (e) => {
@@ -90,73 +108,89 @@ function Owntracks({end, duration, range}) {
 }
 
 
-function Graphs({end, duration, range}) {
+function Graphs({end, duration, slider}) {
 	return (
 		<div className='container'>
-			<Owntracks end={end} duration={duration} range={range} />
+			<Owntracks end={end} duration={duration} slider={slider} />
 		</div>
 	);
 }
 
-function Menu({duration, setDuration, end, setEnd, range, setRange}) {
+function Menu({duration, setDuration, end, setEnd, slider, setSlider}) {
 	const [submenu, setSubmenu] = useState(false);
 	const [showRange, setShowRange] = useState(false);
 
 	const chooseDuration = (x) => {
 		setSubmenu(false);
-		setRange(false);
+		setSlider([0, x.num]);
 		setDuration(x);
 	};
 
 	const chooseEnd = (x) => {
 		setSubmenu(false);
 		const newEnd = x.add(...duration.delta);
-		setRange(false);
+		setSlider([0, duration.num]);
 		setEnd(newEnd);
 	};
 
 	const chooseNow = (x) => {
 		setSubmenu(false);
-		setRange(false);
+		setSlider([0, duration.num]);
 		setEnd(moment());
 	};
 
+	const rangeStart = (x) => {
+		setEnd(moment(range[0]).add(...duration.delta));
+		setSlider([0, duration.num]);
+	};
+
+	const rangeEnd = (x) => {
+		setEnd(moment(range[1]));
+		setSlider([0, duration.num]);
+	};
+
 	const next = () => {
 		setSubmenu(false);
-		setRange(false);
+		setSlider([0, duration.num]);
 		setEnd(prevEnd => moment(prevEnd).add(...duration.delta));
 	}
 
 	const prev = () => {
 		setSubmenu(false);
-		setRange(false);
+		setSlider([0, duration.num]);
 		setEnd(prevEnd => moment(prevEnd).subtract(...duration.delta));
 	}
 
-	const onSlider = (slider) => {
-		console.log(slider);
-		// good luck remembering how this works
-		const lowOffset = slider[0] * duration.secs - duration.num * duration.secs;
-		const highOffset = slider[1] * duration.secs - duration.num * duration.secs;
+	const range = parseSlider(end, duration, slider);
 
-		const low = moment.unix(end.unix() + lowOffset);
-		const high = moment.unix(end.unix() + highOffset);
-
-		const lowStr = low.utc().format('YYYY-MM-DDTHH:mm:ss[Z]');
-		const highStr = high.utc().format('YYYY-MM-DDTHH:mm:ss[Z]');
-
-		console.log(lowStr, highStr);
-		setRange([lowStr, highStr]);
-
-	}
+	const rangeTime = (x) => {
+		if (new Date().getTimezoneOffset()) {  // non-librewolf browser
+			return moment(x).format('lll');  // default to browser's TZ
+		} else {
+			return moment(x).tz('America/Edmonton').format('lll');
+		}
+	};
 
 	return (
 		<div className='menu'>
-			{showRange && <div className='range'>
-				{moment(range[0]).format('lll')} - {moment(range[1]).format('lll')}
+			{(showRange || !!submenu) && <div className='range'>
+				{rangeTime(range[0])} - {rangeTime(range[1])}
 			</div>}
 
-			{submenu ?
+			<div className='time-slider'>
+				<RangeSlider
+					min={0}
+					max={duration.num}
+					value={slider}
+					onInput={setSlider}
+					onThumbDragStart={() => setShowRange(true)}
+					onThumbDragEnd={() => setShowRange(false)}
+					onRangeDragStart={() => setShowRange(true)}
+					onRangeDragEnd={() => setShowRange(false)}
+				/>
+			</div>
+
+			{!!submenu &&
 				<div className='submenu'>
 					{submenu === 'end' &&
 						<>
@@ -174,6 +208,8 @@ function Menu({duration, setDuration, end, setEnd, range, setRange}) {
 							</div>
 
 							<button onClick={chooseNow}>Jump to Now</button>
+							<button onClick={rangeStart}>Shift to Range Start</button>
+							<button onClick={rangeEnd}>Shift to Range End</button>
 						</>
 					}
 
@@ -190,20 +226,6 @@ function Menu({duration, setDuration, end, setEnd, range, setRange}) {
 						</>
 					}
 				</div>
-			:
-				<div className='time-slider'>
-					<RangeSlider
-						min={0}
-						max={duration.num}
-						defaultValue={[0, duration.num]}
-						onInput={onSlider}
-						onThumbDragStart={() => setShowRange(true)}
-						onThumbDragEnd={() => setShowRange(false)}
-						onRangeDragStart={() => setShowRange(true)}
-						onRangeDragEnd={() => setShowRange(false)}
-					/>
-
-				</div>
 			}
 
 			<div className='menu-container'>
@@ -232,7 +254,7 @@ function Menu({duration, setDuration, end, setEnd, range, setRange}) {
 function App() {
 	const [duration, setDuration] = useState(durations[0]);
 	const [end, setEnd] = useState(moment());
-	const [range, setRange] = useState(false);
+	const [slider, setSlider] = useState([0, duration.num]);
 
 	return (
 		<div>
@@ -241,14 +263,14 @@ function App() {
 				setDuration={setDuration}
 				end={end}
 				setEnd={setEnd}
-				range={range}
-				setRange={setRange}
+				slider={slider}
+				setSlider={setSlider}
 			/>
 
 			<Graphs
 				end={end}
 				duration={duration}
-				range={range}
+				slider={slider}
 			/>
 		</div>
 	);