Since the division of the Korean Peninsula in 1948, South and North Korea have independently developed their astronomical almanacs: Ryeokseo at the Korea Astronomy and Space Science Institute in South Korea and Cheonmunryeok at the Pyongyang Astronomical Observatory in North Korea. This study compares Ryeokseo and Cheonmunryeok for the year 2015, focusing on publication systems, content, terminology, and differences in data calculation methods. Additionally, it examines the calendars of South and North Korea from 2018 to 2023, analyzing similarities and differences in the representation of calendrical dates, public holidays, and other related aspects. The findings reveal that while the structure and content of the astronomical almanacs are similar in both countries, notable variances exist in the versions of ephemerides, time scales, and calculation precision. Consequently, identical data points are often recorded with slightly different values in each country's almanacs. Furthermore, approximately 28% of the terms used in North Korea's astronomical almanac are either not utilized in South Korea or have different definitions. Regarding calendar systems, those of South and North Korea are largely similar, resulting in no significant discrepancies in dates. However, there are notable differences in the observance of public holidays. While traditional holidays are common to both, most holidays are distinctively celebrated. Notably, North Korea does not observe religious holidays, and many of its holidays are associated with the regime.

1. 서론
2. 북한의 천문력
    2.1. 천문력 구성과 발간 체계
    2.2. 천문력과 역서의 내용 비교
3. 남북한 천문 역서 차이점 분석
    3.1. 역서와 천문력 용어 비교
    3.2. 역서와 천문력 데이터 차이의 원인
4. 북한의 달력 분석
    4.1. 북한 달력의 성격
    4.2. 북한의 공휴일
5. 결론 및 토의
ACKNOWLEDGMENT
REFERENCES

• 박한얼(한국천문연구원) | HAN-EARL PARK (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• 양홍진(한국천문연구원, 과학기술연합대학원대학교) | HONG-JIN YANG (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea, University of Science and Technology, Daejeon 34055, Korea) Corresponding author
• 손동효(한국천문연구원) | DONG-HYO SOHN (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• 강현우(한국천문연구원) | HYUNWOO KANG (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea)
• 이효준(한국천문연구원, 과학기술연합대학원대학교) | HYOJUN LEE (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea, University of Science and Technology, Daejeon 34055, Korea)
• 임인성(한국천문연구원, 통일과학기술연구소) | INSUNG YIM (Korea Astronomy and Space Science Institute, Daejeon 34055, Korea, Institute of Unification Science and Technology)