timings, 60
<link rel="help" href="https://w3c.github.io/webvtt/#collect-a-webvtt-timestamp">

assert_equals(cues.length, 2);

assert_equals(cues[0].text, 'text1');
assert_equals(cues[0].startTime, 0);
assert_equals(cues[0].endTime, 216001);

assert_equals(cues[1].text, 'text2');
assert_equals(cues[1].startTime, 216000);
assert_equals(cues[1].endTime, 216001);

===
WEBVTT

00:00:60.000 --> 00:00:01.000
invalid

00:60:00.000 --> 00:00:01.000
invalid

00:00:00.000 --> 00:00:60.000
invalid

00:00:00.000 --> 00:60:00.000
invalid

00:00:00.000 --> 60:00:01.000
text1

60:00:00.000 --> 60:00:01.000
text2