What is the solar calendar on the 18th day of the first lunar month?

February eighth. According to the perpetual calendar, the 18th solar calendar of the first lunar month in 2023 is February 8th. The lunar calendar, that is, the current traditional calendar in China, belongs to the yin-yang calendar, that is, the lunar calendar and the solar calendar. According to the change cycle of the moon phases, each moon phase changes to one month, taking the tropical year of the sun as the length of a year, and adding 24 solar terms and setting leap months to make the average calendar year adapt to the tropical year.