{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":4.0,"best_label":"good","best_window":"19:30\u201323:30","dark_hours":10.18,"date":"2028-02-17","moon_free_dark_hours":7.12,"moon_illumination":44,"moon_separation":173.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.83,"best_label":"good","best_window":"19:35\u201323:25","dark_hours":10.14,"date":"2028-02-18","moon_free_dark_hours":8.07,"moon_illumination":34,"moon_separation":161.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"18:15","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.83,"best_label":"good","best_window":"19:35\u201323:25","dark_hours":10.1,"date":"2028-02-19","moon_free_dark_hours":8.88,"moon_illumination":25,"moon_separation":148.9,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":72.5,"transit_local":"18:15","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.75,"best_label":"good","best_window":"19:35\u201323:20","dark_hours":10.06,"date":"2028-02-20","moon_free_dark_hours":9.55,"moon_illumination":17,"moon_separation":136.7,"score":null,"score_astronomy":97,"score_weather":null,"transit_alt":72.5,"transit_local":"18:10","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.67,"best_label":"good","best_window":"19:35\u201323:15","dark_hours":10.02,"date":"2028-02-21","moon_free_dark_hours":10.0,"moon_illumination":10,"moon_separation":124.7,"score":null,"score_astronomy":96,"score_weather":null,"transit_alt":72.5,"transit_local":"18:05","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.58,"best_label":"good","best_window":"19:35\u201323:10","dark_hours":9.98,"date":"2028-02-22","moon_free_dark_hours":9.97,"moon_illumination":6,"moon_separation":112.8,"score":null,"score_astronomy":94,"score_weather":null,"transit_alt":72.5,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.5,"best_label":"good","best_window":"19:40\u201323:10","dark_hours":9.93,"date":"2028-02-23","moon_free_dark_hours":9.92,"moon_illumination":2,"moon_separation":101.0,"score":null,"score_astronomy":91,"score_weather":null,"transit_alt":72.5,"transit_local":"17:55","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":3.42,"best_label":"good","best_window":"19:40\u201323:05","dark_hours":9.89,"date":"2028-02-24","moon_free_dark_hours":9.87,"moon_illumination":0,"moon_separation":89.2,"score":null,"score_astronomy":89,"score_weather":null,"transit_alt":72.5,"transit_local":"17:55","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":3.33,"best_label":"good","best_window":"19:40\u201323:00","dark_hours":9.85,"date":"2028-02-25","moon_free_dark_hours":9.83,"moon_illumination":0,"moon_separation":77.3,"score":null,"score_astronomy":87,"score_weather":null,"transit_alt":72.5,"transit_local":"17:50","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":3.25,"best_label":"good","best_window":"19:40\u201322:55","dark_hours":9.8,"date":"2028-02-26","moon_free_dark_hours":9.78,"moon_illumination":2,"moon_separation":65.5,"score":null,"score_astronomy":86,"score_weather":null,"transit_alt":72.5,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":3.08,"best_label":"good","best_window":"19:45\u201322:50","dark_hours":9.76,"date":"2028-02-27","moon_free_dark_hours":9.18,"moon_illumination":6,"moon_separation":53.5,"score":null,"score_astronomy":80,"score_weather":null,"transit_alt":72.5,"transit_local":"17:40","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":3.08,"best_label":"good","best_window":"19:45\u201322:50","dark_hours":9.71,"date":"2028-02-28","moon_free_dark_hours":8.13,"moon_illumination":11,"moon_separation":41.5,"score":null,"score_astronomy":74,"score_weather":null,"transit_alt":72.5,"transit_local":"17:35","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":3.0,"best_label":"good","best_window":"19:45\u201322:45","dark_hours":9.67,"date":"2028-02-29","moon_free_dark_hours":7.07,"moon_illumination":18,"moon_separation":29.3,"score":null,"score_astronomy":64,"score_weather":null,"transit_alt":72.5,"transit_local":"17:35","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":2.75,"best_label":"good","best_window":"19:45\u201322:30","dark_hours":9.62,"date":"2028-03-01","moon_free_dark_hours":5.95,"moon_illumination":26,"moon_separation":16.9,"score":null,"score_astronomy":53,"score_weather":null,"transit_alt":72.5,"transit_local":"17:30","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":2.42,"best_label":"good","best_window":"19:50\u201322:15","dark_hours":9.58,"date":"2028-03-02","moon_free_dark_hours":4.83,"moon_illumination":35,"moon_separation":4.2,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":72.5,"transit_local":"17:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.33,"best_label":"good","best_window":"19:50\u201321:10","dark_hours":9.53,"date":"2028-03-03","moon_free_dark_hours":3.73,"moon_illumination":45,"moon_separation":8.7,"score":null,"score_astronomy":32,"score_weather":null,"transit_alt":72.5,"transit_local":"17:20","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":2.92,"best_label":"marginal","best_window":"19:50\u201322:45","dark_hours":9.48,"date":"2028-03-04","moon_free_dark_hours":2.68,"moon_illumination":56,"moon_separation":22.0,"score":null,"score_astronomy":22,"score_weather":null,"transit_alt":72.5,"transit_local":"17:15","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":2.67,"best_label":"marginal","best_window":"19:50\u201322:30","dark_hours":9.44,"date":"2028-03-05","moon_free_dark_hours":1.77,"moon_illumination":67,"moon_separation":35.7,"score":null,"score_astronomy":17,"score_weather":null,"transit_alt":72.5,"transit_local":"17:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":2.5,"best_label":"marginal","best_window":"19:55\u201322:25","dark_hours":9.39,"date":"2028-03-06","moon_free_dark_hours":0.97,"moon_illumination":77,"moon_separation":49.9,"score":null,"score_astronomy":16,"score_weather":null,"transit_alt":72.5,"transit_local":"17:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.5,"best_label":"marginal","best_window":"19:55\u201322:25","dark_hours":9.34,"date":"2028-03-07","moon_free_dark_hours":0.28,"moon_illumination":86,"moon_separation":64.5,"score":null,"score_astronomy":18,"score_weather":null,"transit_alt":72.5,"transit_local":"17:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.08,"best_label":"marginal","best_window":"19:20\u201322:25","dark_hours":9.29,"date":"2028-03-08","moon_free_dark_hours":0.0,"moon_illumination":93,"moon_separation":79.4,"score":null,"score_astronomy":23,"score_weather":null,"transit_alt":72.5,"transit_local":"17:00","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.25,"best_label":"good","best_window":"19:55\u201321:10","dark_hours":9.25,"date":"2028-03-09","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":94.6,"score":null,"score_astronomy":30,"score_weather":null,"transit_alt":72.5,"transit_local":"17:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.83,"best_label":"good","best_window":"19:55\u201321:45","dark_hours":9.2,"date":"2028-03-10","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":109.8,"score":null,"score_astronomy":37,"score_weather":null,"transit_alt":72.5,"transit_local":"16:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":1.83,"best_label":"good","best_window":"20:00\u201321:50","dark_hours":9.15,"date":"2028-03-11","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":124.9,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":72.5,"transit_local":"16:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":1.83,"best_label":"good","best_window":"20:00\u201321:50","dark_hours":9.1,"date":"2028-03-12","moon_free_dark_hours":0.68,"moon_illumination":95,"moon_separation":139.8,"score":null,"score_astronomy":47,"score_weather":null,"transit_alt":72.5,"transit_local":"16:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":1.92,"best_label":"good","best_window":"20:00\u201321:55","dark_hours":9.05,"date":"2028-03-13","moon_free_dark_hours":1.95,"moon_illumination":88,"moon_separation":154.3,"score":null,"score_astronomy":47,"score_weather":null,"transit_alt":72.5,"transit_local":"16:40","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":1.83,"best_label":"good","best_window":"20:00\u201321:50","dark_hours":9.0,"date":"2028-03-14","moon_free_dark_hours":3.2,"moon_illumination":80,"moon_separation":168.3,"score":null,"score_astronomy":45,"score_weather":null,"transit_alt":72.5,"transit_local":"16:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":1.67,"best_label":"good","best_window":"20:05\u201321:45","dark_hours":8.95,"date":"2028-03-15","moon_free_dark_hours":4.35,"moon_illumination":70,"moon_separation":178.1,"score":null,"score_astronomy":42,"score_weather":null,"transit_alt":72.5,"transit_local":"16:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":1.58,"best_label":"good","best_window":"20:05\u201321:40","dark_hours":8.9,"date":"2028-03-16","moon_free_dark_hours":5.38,"moon_illumination":60,"moon_separation":165.0,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":72.5,"transit_local":"16:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":1.5,"best_label":"good","best_window":"20:05\u201321:35","dark_hours":8.85,"date":"2028-03-17","moon_free_dark_hours":6.27,"moon_illumination":50,"moon_separation":152.4,"score":null,"score_astronomy":39,"score_weather":null,"transit_alt":72.5,"transit_local":"16:25","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":"2028-02-17","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"}}