Is the winter solstice based on the lunar calendar or the solar calendar? Why is the winter solstice based on the solar calendar?

Since ancient times, the Winter Solstice has been one of the most important solar terms. I want to know how the time of the Winter Solstice is determined, is it based on the lunar calendar or the solar calendar? Next, let’s take a look together.

Is the Winter Solstice based on the lunar calendar or the solar calendar?

General Overview

The winter solstice is calculated according to the solar calendar.
When the sun reaches 270° of the ecliptic longitude, the winter solstice falls on December 22 every year. If it is a leap year, it will be moved forward one day to December 21. The 24 solar terms are a supplementary calendar established in ancient China to guide agricultural activities. It was formed during the Spring and Autumn Period and the Warring States Period. The 24 solar terms are determined based on the sun's movement cycle, so the dates of the 24 solar terms are all based on the Gregorian calendar.

Specific timetable

The winter solstice of 2017 is at 00:27:53 on December 22, the fifth day of the eleventh month of the lunar calendar in 2017.
The winter solstice of 2018 is on December 22, 06:22:38, the 16th day of the 11th month of the lunar calendar in 2018.
The winter solstice of 2019 is at 12:19:18 on December 22, the 27th day of the 11th month of the lunar calendar in 2019.
2020 Winter Solstice Time: December 21, 18:02:12, the seventh day of the eleventh month of the lunar calendar 2020
2021 Winter Solstice Time: December 21, 23:59:09, the 18th day of the 11th month of the lunar calendar 2021
The winter solstice of 2022 is on December 22, 05:48:01, the 29th day of the 11th month of the lunar calendar in 2022.
The winter solstice in 2023 is at 11:27:09 on December 22, the tenth day of the eleventh month of the lunar calendar in 2023.
The winter solstice in 2024 is at 17:20:20 on December 21, the 21st day of the 11th month in the lunar calendar of 2024.
The winter solstice in 2025 is at 23:02:48 on December 21, the second day of the first lunar month in 2025.