diff --git a/restreamer/restreamer/main.py b/restreamer/restreamer/main.py
index c5bc873..7f32ad5 100644
--- a/restreamer/restreamer/main.py
+++ b/restreamer/restreamer/main.py
@@ -1,4 +1,5 @@
 
+import datetime
 import errno
 import functools
 import json
@@ -85,6 +86,17 @@ def list_segments(stream, variant, hour):
 	return json.dumps(listdir(path, error=False))
 
 
+def time_range_for_variant(stream, variant):
+	"""Returns earliest and latest times that the given variant has segments for
+	(up to hour resolution), or 404 if it doesn't exist / is empty."""
+	hours = listdir(os.path.join(app.static_folder, stream, variant))
+	if not hours:
+		abort(404)
+	first, last = min(hours), max(hours)
+	# note last hour parses to _start_ of that hour, so we add 1h to go to end of that hour
+	return dateutil.parser.parse(first), dateutil.parser.parse(last) + datetime.timedelta(hours=1)
+
+
 @app.route('/playlist/<stream>.m3u8')
 @has_path_args
 def generate_master_playlist(stream):
@@ -93,11 +105,24 @@ def generate_master_playlist(stream):
 		start, end: The time to begin and end the stream at.
 			See generate_media_playlist for details.
 	"""
+	start = dateutil.parser.parse(request.args['start']) if 'start' in request.args else None
+	end = dateutil.parser.parse(request.args['end']) if 'end' in request.args else None
 	variants = listdir(os.path.join(app.static_folder, stream))
-	playlists = {
-		variant: url_for('generate_media_playlist', stream=stream, variant=variant, **request.args)
-		for variant in variants
-	}
+
+	playlists = {}
+	for variant in variants:
+		# If start or end are given, try to restrict offered variants to ones which exist for that
+		# time range.
+		if start is not None or end is not None:
+			first, last = time_range_for_variant(stream, variant)
+			if start is not None and last < start:
+				continue # last time for variant is before our start time, don't offer variant
+			if end is not None and end < first:
+				continue # our end time is before first time for variant, don't offer variant
+		playlists[variant] = url_for(
+			'generate_media_playlist', stream=stream, variant=variant, **request.args
+		)
+
 	return generate_hls.generate_master(playlists)