 new calendar was used in month 5, the conjunction day moved one day earlier, turning month 4 into a short month. Month 5 was a short month in the new calendar. As a result, months 3, 4, 5 in <span class="nowrap">N<sub>-103</sub></span> all had 29 days. This is impossible for any calendar based on the <i>p&#237;ngshu&#242;</i> rule (based on the mean motions of the Moon and Sun), and could only occur when switching to a new calendar. If the switch is changed to month 6, month 5 will have 28 days, which is a