{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":8.75,"best_label":"good","best_window":"18:35\u201303:20","dark_hours":11.49,"date":"2030-12-15","moon_free_dark_hours":3.78,"moon_illumination":70,"moon_separation":90.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:30","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":8.83,"best_label":"good","best_window":"18:35\u201303:25","dark_hours":11.5,"date":"2030-12-16","moon_free_dark_hours":4.8,"moon_illumination":61,"moon_separation":102.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:25","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":8.92,"best_label":"good","best_window":"18:35\u201303:30","dark_hours":11.5,"date":"2030-12-17","moon_free_dark_hours":5.85,"moon_illumination":51,"moon_separation":115.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:25","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":8.83,"best_label":"good","best_window":"18:35\u201303:25","dark_hours":11.5,"date":"2030-12-18","moon_free_dark_hours":6.95,"moon_illumination":40,"moon_separation":128.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":8.83,"best_label":"good","best_window":"18:35\u201303:25","dark_hours":11.51,"date":"2030-12-19","moon_free_dark_hours":8.08,"moon_illumination":30,"moon_separation":142.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:15","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":8.75,"best_label":"good","best_window":"18:35\u201303:20","dark_hours":11.51,"date":"2030-12-20","moon_free_dark_hours":9.27,"moon_illumination":20,"moon_separation":156.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":8.75,"best_label":"good","best_window":"18:35\u201303:20","dark_hours":11.51,"date":"2030-12-21","moon_free_dark_hours":10.47,"moon_illumination":11,"moon_separation":170.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:10","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":8.67,"best_label":"good","best_window":"18:35\u201303:15","dark_hours":11.51,"date":"2030-12-22","moon_free_dark_hours":11.5,"moon_illumination":5,"moon_separation":172.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:05","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":8.5,"best_label":"good","best_window":"18:40\u201303:10","dark_hours":11.51,"date":"2030-12-23","moon_free_dark_hours":11.48,"moon_illumination":1,"moon_separation":158.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"22:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":8.42,"best_label":"good","best_window":"18:40\u201303:05","dark_hours":11.5,"date":"2030-12-24","moon_free_dark_hours":11.48,"moon_illumination":0,"moon_separation":143.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":8.42,"best_label":"good","best_window":"18:40\u201303:05","dark_hours":11.5,"date":"2030-12-25","moon_free_dark_hours":11.48,"moon_illumination":2,"moon_separation":128.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":8.33,"best_label":"good","best_window":"18:40\u201303:00","dark_hours":11.5,"date":"2030-12-26","moon_free_dark_hours":10.85,"moon_illumination":7,"moon_separation":113.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:50","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":8.25,"best_label":"good","best_window":"18:40\u201302:55","dark_hours":11.49,"date":"2030-12-27","moon_free_dark_hours":9.62,"moon_illumination":14,"moon_separation":98.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:45","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":8.17,"best_label":"good","best_window":"18:40\u201302:50","dark_hours":11.48,"date":"2030-12-28","moon_free_dark_hours":8.43,"moon_illumination":23,"moon_separation":84.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:40","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":8.08,"best_label":"good","best_window":"18:40\u201302:45","dark_hours":11.48,"date":"2030-12-29","moon_free_dark_hours":7.3,"moon_illumination":33,"moon_separation":70.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"21:35","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":8.08,"best_label":"good","best_window":"18:40\u201302:45","dark_hours":11.47,"date":"2030-12-30","moon_free_dark_hours":6.22,"moon_illumination":44,"moon_separation":57.8,"score":null,"score_astronomy":97,"score_weather":null,"transit_alt":72.5,"transit_local":"21:30","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":7.92,"best_label":"good","best_window":"18:45\u201302:40","dark_hours":11.46,"date":"2030-12-31","moon_free_dark_hours":5.18,"moon_illumination":54,"moon_separation":45.1,"score":null,"score_astronomy":89,"score_weather":null,"transit_alt":72.5,"transit_local":"21:30","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.08,"best_label":"good","best_window":"22:30\u201302:35","dark_hours":11.45,"date":"2031-01-01","moon_free_dark_hours":4.17,"moon_illumination":64,"moon_separation":32.7,"score":null,"score_astronomy":81,"score_weather":null,"transit_alt":72.5,"transit_local":"21:25","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":8.17,"best_label":"marginal","best_window":"18:45\u201302:55","dark_hours":11.44,"date":"2031-01-02","moon_free_dark_hours":3.17,"moon_illumination":72,"moon_separation":20.7,"score":null,"score_astronomy":53,"score_weather":null,"transit_alt":72.5,"transit_local":"21:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":7.92,"best_label":"marginal","best_window":"18:45\u201302:40","dark_hours":11.43,"date":"2031-01-03","moon_free_dark_hours":2.2,"moon_illumination":81,"moon_separation":9.1,"score":null,"score_astronomy":39,"score_weather":null,"transit_alt":72.5,"transit_local":"21:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":7.67,"best_label":"marginal","best_window":"18:45\u201302:25","dark_hours":11.42,"date":"2031-01-04","moon_free_dark_hours":1.28,"moon_illumination":88,"moon_separation":4.9,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":72.5,"transit_local":"21:15","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.83,"best_label":"marginal","best_window":"18:45\u201320:35","dark_hours":11.4,"date":"2031-01-05","moon_free_dark_hours":0.43,"moon_illumination":93,"moon_separation":15.7,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":72.5,"transit_local":"21:10","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.75,"best_label":"marginal","best_window":"18:50\u201320:35","dark_hours":11.39,"date":"2031-01-06","moon_free_dark_hours":0.0,"moon_illumination":97,"moon_separation":27.4,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":72.5,"transit_local":"21:05","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.25,"best_label":"marginal","best_window":"18:50\u201323:05","dark_hours":11.38,"date":"2031-01-07","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":39.2,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":72.5,"transit_local":"21:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.92,"best_label":"marginal","best_window":"18:50\u201301:45","dark_hours":11.36,"date":"2031-01-08","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":51.1,"score":null,"score_astronomy":48,"score_weather":null,"transit_alt":72.5,"transit_local":"20:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.83,"best_label":"good","best_window":"18:50\u201320:40","dark_hours":11.34,"date":"2031-01-09","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":63.1,"score":null,"score_astronomy":69,"score_weather":null,"transit_alt":72.5,"transit_local":"20:55","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.42,"best_label":"good","best_window":"18:50\u201323:15","dark_hours":11.33,"date":"2031-01-10","moon_free_dark_hours":0.38,"moon_illumination":96,"moon_separation":75.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"20:50","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.83,"best_label":"good","best_window":"18:50\u201300:40","dark_hours":11.31,"date":"2031-01-11","moon_free_dark_hours":1.37,"moon_illumination":91,"moon_separation":87.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"20:45","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":6.58,"best_label":"good","best_window":"18:55\u201301:30","dark_hours":11.29,"date":"2031-01-12","moon_free_dark_hours":2.37,"moon_illumination":84,"moon_separation":99.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"20:40","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.67,"best_label":"good","best_window":"18:55\u201301:35","dark_hours":11.27,"date":"2031-01-13","moon_free_dark_hours":3.4,"moon_illumination":76,"moon_separation":112.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"20:35","verdict":"unknown","weather_source":"none","weekday":"Mon"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2030-12-15","target":{"common_name":"Seven Sisters","dec":24.11388889,"name":"Cl Melotte 22","ra":56.60083333,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=M45","source":"sesame","type":"OpC","type_text":"open cluster"}}