It's true! Someone on Reddit actually did the math: "I just timed 60 seconds of the track, and there were 48 ticks, so each tick interval is 1.25 seconds. Every hour on Miller is about 7 years on Earth. There are 3,600 seconds in an hour (and 86,400 seconds in a day x 365.25 days in a year x 7 years on Earth per hour on Miller, or roughly 221,000,000 seconds in 7 years). This gives us a conversion factor of 221,000,000/3,600 ≈ 61,400 seconds which pass on Earth for every second spent on Miller. Multiply this by the interval between each tick, and you get 77,000 Earth seconds, about 21 hours. So, each tick you hear is a whole day passing on Earth."