{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":1.75,"best_label":"good","best_window":"03:10\u201304:55","dark_hours":6.92,"date":"2043-08-20","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":88.3,"score":null,"score_astronomy":39,"score_weather":null,"transit_alt":72.5,"transit_local":"07:10","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":0.42,"best_label":"good","best_window":"04:30\u201304:55","dark_hours":6.98,"date":"2043-08-21","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":74.7,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":72.6,"transit_local":"07:10","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.17,"best_label":"marginal","best_window":"01:50\u201305:00","dark_hours":7.04,"date":"2043-08-22","moon_free_dark_hours":0.0,"moon_illumination":94,"moon_separation":60.8,"score":null,"score_astronomy":23,"score_weather":null,"transit_alt":72.6,"transit_local":"07:05","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.08,"best_label":"marginal","best_window":"01:55\u201305:00","dark_hours":7.1,"date":"2043-08-23","moon_free_dark_hours":0.0,"moon_illumination":87,"moon_separation":46.8,"score":null,"score_astronomy":18,"score_weather":null,"transit_alt":72.6,"transit_local":"07:00","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.17,"best_label":"marginal","best_window":"01:50\u201305:00","dark_hours":7.15,"date":"2043-08-24","moon_free_dark_hours":0.18,"moon_illumination":78,"moon_separation":32.7,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":72.5,"transit_local":"06:55","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.42,"best_label":"marginal","best_window":"01:35\u201305:00","dark_hours":7.21,"date":"2043-08-25","moon_free_dark_hours":0.67,"moon_illumination":68,"moon_separation":18.5,"score":null,"score_astronomy":21,"score_weather":null,"transit_alt":72.5,"transit_local":"06:55","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.75,"best_label":"marginal","best_window":"01:20\u201305:05","dark_hours":7.27,"date":"2043-08-26","moon_free_dark_hours":1.25,"moon_illumination":57,"moon_separation":4.3,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":72.6,"transit_local":"06:50","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.92,"best_label":"good","best_window":"02:10\u201305:05","dark_hours":7.32,"date":"2043-08-27","moon_free_dark_hours":1.97,"moon_illumination":46,"moon_separation":9.9,"score":null,"score_astronomy":43,"score_weather":null,"transit_alt":72.6,"transit_local":"06:45","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.25,"best_label":"good","best_window":"01:50\u201305:05","dark_hours":7.38,"date":"2043-08-28","moon_free_dark_hours":2.87,"moon_illumination":34,"moon_separation":24.0,"score":null,"score_astronomy":57,"score_weather":null,"transit_alt":72.6,"transit_local":"06:40","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.67,"best_label":"good","best_window":"01:30\u201305:10","dark_hours":7.44,"date":"2043-08-29","moon_free_dark_hours":3.95,"moon_illumination":24,"moon_separation":38.0,"score":null,"score_astronomy":74,"score_weather":null,"transit_alt":72.5,"transit_local":"06:35","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.75,"best_label":"good","best_window":"01:25\u201305:10","dark_hours":7.49,"date":"2043-08-30","moon_free_dark_hours":5.18,"moon_illumination":15,"moon_separation":52.0,"score":null,"score_astronomy":88,"score_weather":null,"transit_alt":72.5,"transit_local":"06:35","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.75,"best_label":"good","best_window":"01:25\u201305:10","dark_hours":7.55,"date":"2043-08-31","moon_free_dark_hours":6.47,"moon_illumination":8,"moon_separation":65.8,"score":null,"score_astronomy":96,"score_weather":null,"transit_alt":72.6,"transit_local":"06:30","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.83,"best_label":"good","best_window":"01:20\u201305:10","dark_hours":7.6,"date":"2043-09-01","moon_free_dark_hours":7.58,"moon_illumination":3,"moon_separation":79.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"06:25","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.0,"best_label":"good","best_window":"01:15\u201305:15","dark_hours":7.66,"date":"2043-09-02","moon_free_dark_hours":7.63,"moon_illumination":0,"moon_separation":92.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"06:20","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.08,"best_label":"good","best_window":"01:10\u201305:15","dark_hours":7.72,"date":"2043-09-03","moon_free_dark_hours":7.7,"moon_illumination":0,"moon_separation":106.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"06:15","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.08,"best_label":"good","best_window":"01:10\u201305:15","dark_hours":7.77,"date":"2043-09-04","moon_free_dark_hours":7.75,"moon_illumination":2,"moon_separation":118.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"06:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.17,"best_label":"good","best_window":"01:05\u201305:15","dark_hours":7.83,"date":"2043-09-05","moon_free_dark_hours":7.8,"moon_illumination":6,"moon_separation":131.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"06:10","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.33,"best_label":"good","best_window":"01:00\u201305:20","dark_hours":7.88,"date":"2043-09-06","moon_free_dark_hours":7.87,"moon_illumination":11,"moon_separation":143.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"06:05","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":4.42,"best_label":"good","best_window":"00:55\u201305:20","dark_hours":7.94,"date":"2043-09-07","moon_free_dark_hours":7.92,"moon_illumination":18,"moon_separation":156.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"06:00","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.5,"best_label":"good","best_window":"00:50\u201305:20","dark_hours":7.99,"date":"2043-09-08","moon_free_dark_hours":7.7,"moon_illumination":26,"moon_separation":167.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"06:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.5,"best_label":"good","best_window":"00:50\u201305:20","dark_hours":8.05,"date":"2043-09-09","moon_free_dark_hours":7.25,"moon_illumination":35,"moon_separation":179.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.67,"best_label":"good","best_window":"00:45\u201305:25","dark_hours":8.1,"date":"2043-09-10","moon_free_dark_hours":6.72,"moon_illumination":44,"moon_separation":168.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:50","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.75,"best_label":"good","best_window":"00:40\u201305:25","dark_hours":8.15,"date":"2043-09-11","moon_free_dark_hours":6.02,"moon_illumination":54,"moon_separation":156.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:45","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":4.83,"best_label":"good","best_window":"00:35\u201305:25","dark_hours":8.21,"date":"2043-09-12","moon_free_dark_hours":5.17,"moon_illumination":63,"moon_separation":144.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"05:40","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":4.75,"best_label":"good","best_window":"00:40\u201305:25","dark_hours":8.26,"date":"2043-09-13","moon_free_dark_hours":4.18,"moon_illumination":72,"moon_separation":132.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"05:40","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":4.92,"best_label":"good","best_window":"00:35\u201305:30","dark_hours":8.31,"date":"2043-09-14","moon_free_dark_hours":3.1,"moon_illumination":81,"moon_separation":119.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:35","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":4.83,"best_label":"good","best_window":"00:40\u201305:30","dark_hours":8.37,"date":"2043-09-15","moon_free_dark_hours":1.93,"moon_illumination":88,"moon_separation":106.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:30","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":4.75,"best_label":"good","best_window":"00:45\u201305:30","dark_hours":8.42,"date":"2043-09-16","moon_free_dark_hours":0.73,"moon_illumination":94,"moon_separation":93.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.6,"transit_local":"05:25","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":3.33,"best_label":"good","best_window":"02:10\u201305:30","dark_hours":8.47,"date":"2043-09-17","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":79.9,"score":null,"score_astronomy":72,"score_weather":null,"transit_alt":72.5,"transit_local":"05:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.17,"best_label":"good","best_window":"04:25\u201305:35","dark_hours":8.52,"date":"2043-09-18","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":65.9,"score":null,"score_astronomy":51,"score_weather":null,"transit_alt":72.6,"transit_local":"05:20","verdict":"unknown","weather_source":"none","weekday":"Fri"}],"note":"score_astronomy for every night; score_weather/score only where a forecast (next 4 days) or ERA5 history exists \u2014 null otherwise","start":"2043-08-20","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"}}