Choi et al. (Advances in Space Research 62, 3237–3248) studied the sunrise and sunset times of the Chóngxiū-Dàmínglì, but they made a small mistake in deriving the formula for them, which caused a maximum error of 1.73 seconds in the current unit of time. They also suggested that the sunrise and sunset times of the Chóngxiū-Dàmínglì were based on observations at the capital of the Northern Song dynasty, but it turns out that they were based on the same observations as the older Chinese calendar Xuānmínglì.