《晋书·志·第七章》
以夜半入历日余，乘以损益率，除以周法五千九百六十九，除不尽的为余数，以所得商数增减入历天对应的盈缩积，余数没有对应的来减，则从盈缩积中拿出一乘以周法五千九百六十九，再减之，最后所得即为夜半盈缩。
以夜半入历日余，乘损益率，如周法得一，不尽为余，以损益缩积，余无所损，破全为法损之，为夜半盈缩也。
Multiply the remaining time from half-night to the calendar day with rate of loss and gain, divide the result by Zhou method 5969, the remaining is the remainder, add or subtract the result to corresponding increase or decrease accumulation in the calendar day, if there isn't corresponding remainder to subtract, then take out one from increase or decrease accumulation, multiply with Zhou method 5969 and subtract again, the final result is the increase or decrease at half-night.