{"calculation_version":"2026-10-10.1","days":30,"nights":[{"best_hours":6.5,"best_label":"good","best_window":"18:35\u201301:05","dark_hours":11.5,"date":"2027-12-16","moon_free_dark_hours":1.67,"moon_illumination":86,"moon_separation":99.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"19:25","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":6.67,"best_label":"good","best_window":"18:35\u201301:15","dark_hours":11.5,"date":"2027-12-17","moon_free_dark_hours":2.95,"moon_illumination":77,"moon_separation":112.2,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"19:20","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":6.75,"best_label":"good","best_window":"18:35\u201301:20","dark_hours":11.5,"date":"2027-12-18","moon_free_dark_hours":4.2,"moon_illumination":66,"moon_separation":124.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"19:15","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":6.67,"best_label":"good","best_window":"18:35\u201301:15","dark_hours":11.51,"date":"2027-12-19","moon_free_dark_hours":5.4,"moon_illumination":55,"moon_separation":135.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"19:15","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.67,"best_label":"good","best_window":"18:35\u201301:15","dark_hours":11.51,"date":"2027-12-20","moon_free_dark_hours":6.58,"moon_illumination":44,"moon_separation":144.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"19:10","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":6.67,"best_label":"good","best_window":"18:35\u201301:15","dark_hours":11.51,"date":"2027-12-21","moon_free_dark_hours":7.77,"moon_illumination":33,"moon_separation":150.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"19:05","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.58,"best_label":"good","best_window":"18:35\u201301:10","dark_hours":11.51,"date":"2027-12-22","moon_free_dark_hours":8.93,"moon_illumination":24,"moon_separation":151.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"19:00","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":6.42,"best_label":"good","best_window":"18:40\u201301:05","dark_hours":11.51,"date":"2027-12-23","moon_free_dark_hours":10.08,"moon_illumination":15,"moon_separation":147.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"18:55","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":6.33,"best_label":"good","best_window":"18:40\u201301:00","dark_hours":11.5,"date":"2027-12-24","moon_free_dark_hours":11.2,"moon_illumination":8,"moon_separation":139.1,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"18:55","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":6.33,"best_label":"good","best_window":"18:40\u201301:00","dark_hours":11.5,"date":"2027-12-25","moon_free_dark_hours":11.48,"moon_illumination":4,"moon_separation":129.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"18:50","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":6.25,"best_label":"good","best_window":"18:40\u201300:55","dark_hours":11.5,"date":"2027-12-26","moon_free_dark_hours":11.48,"moon_illumination":1,"moon_separation":119.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"18:45","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":6.17,"best_label":"good","best_window":"18:40\u201300:50","dark_hours":11.49,"date":"2027-12-27","moon_free_dark_hours":11.47,"moon_illumination":0,"moon_separation":108.7,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"18:40","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":6.08,"best_label":"good","best_window":"18:40\u201300:45","dark_hours":11.49,"date":"2027-12-28","moon_free_dark_hours":11.47,"moon_illumination":1,"moon_separation":98.0,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.5,"transit_local":"18:40","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.0,"best_label":"good","best_window":"18:40\u201300:40","dark_hours":11.48,"date":"2027-12-29","moon_free_dark_hours":11.47,"moon_illumination":4,"moon_separation":87.3,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.6,"transit_local":"18:35","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":6.0,"best_label":"good","best_window":"18:40\u201300:40","dark_hours":11.47,"date":"2027-12-30","moon_free_dark_hours":10.65,"moon_illumination":9,"moon_separation":76.8,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"18:30","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.83,"best_label":"good","best_window":"18:45\u201300:35","dark_hours":11.46,"date":"2027-12-31","moon_free_dark_hours":9.62,"moon_illumination":15,"moon_separation":66.5,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"18:25","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.75,"best_label":"good","best_window":"18:45\u201300:30","dark_hours":11.45,"date":"2028-01-01","moon_free_dark_hours":8.62,"moon_illumination":22,"moon_separation":56.6,"score":null,"score_astronomy":96,"score_weather":null,"transit_alt":89.6,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":5.67,"best_label":"good","best_window":"18:45\u201300:25","dark_hours":11.44,"date":"2028-01-02","moon_free_dark_hours":7.62,"moon_illumination":30,"moon_separation":47.1,"score":null,"score_astronomy":89,"score_weather":null,"transit_alt":89.5,"transit_local":"18:20","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.67,"best_label":"good","best_window":"18:45\u201300:25","dark_hours":11.43,"date":"2028-01-03","moon_free_dark_hours":6.62,"moon_illumination":39,"moon_separation":38.6,"score":null,"score_astronomy":81,"score_weather":null,"transit_alt":89.7,"transit_local":"18:15","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":5.08,"best_label":"good","best_window":"18:45\u201323:50","dark_hours":11.42,"date":"2028-01-04","moon_free_dark_hours":5.6,"moon_illumination":49,"moon_separation":31.8,"score":null,"score_astronomy":69,"score_weather":null,"transit_alt":89.7,"transit_local":"18:10","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":6.0,"best_label":"marginal","best_window":"18:45\u201300:45","dark_hours":11.41,"date":"2028-01-05","moon_free_dark_hours":4.53,"moon_illumination":58,"moon_separation":28.3,"score":null,"score_astronomy":51,"score_weather":null,"transit_alt":89.7,"transit_local":"18:05","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":5.75,"best_label":"marginal","best_window":"18:45\u201300:30","dark_hours":11.4,"date":"2028-01-06","moon_free_dark_hours":3.42,"moon_illumination":68,"moon_separation":29.6,"score":null,"score_astronomy":35,"score_weather":null,"transit_alt":89.5,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":5.33,"best_label":"marginal","best_window":"18:50\u201300:10","dark_hours":11.38,"date":"2028-01-07","moon_free_dark_hours":2.25,"moon_illumination":78,"moon_separation":35.6,"score":null,"score_astronomy":27,"score_weather":null,"transit_alt":89.6,"transit_local":"18:00","verdict":"unknown","weather_source":"none","weekday":"Fri"},{"best_hours":5.08,"best_label":"marginal","best_window":"18:50\u201323:55","dark_hours":11.37,"date":"2028-01-08","moon_free_dark_hours":1.1,"moon_illumination":86,"moon_separation":44.7,"score":null,"score_astronomy":26,"score_weather":null,"transit_alt":89.7,"transit_local":"17:55","verdict":"unknown","weather_source":"none","weekday":"Sat"},{"best_hours":5.0,"best_label":"marginal","best_window":"18:50\u201323:50","dark_hours":11.35,"date":"2028-01-09","moon_free_dark_hours":0.0,"moon_illumination":93,"moon_separation":55.8,"score":null,"score_astronomy":31,"score_weather":null,"transit_alt":89.7,"transit_local":"17:50","verdict":"unknown","weather_source":"none","weekday":"Sun"},{"best_hours":5.08,"best_label":"marginal","best_window":"18:50\u201323:55","dark_hours":11.33,"date":"2028-01-10","moon_free_dark_hours":0.0,"moon_illumination":98,"moon_separation":68.1,"score":null,"score_astronomy":41,"score_weather":null,"transit_alt":89.6,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Mon"},{"best_hours":2.17,"best_label":"good","best_window":"18:50\u201321:00","dark_hours":11.31,"date":"2028-01-11","moon_free_dark_hours":0.0,"moon_illumination":100,"moon_separation":81.0,"score":null,"score_astronomy":56,"score_weather":null,"transit_alt":89.5,"transit_local":"17:45","verdict":"unknown","weather_source":"none","weekday":"Tue"},{"best_hours":3.5,"best_label":"good","best_window":"18:55\u201322:25","dark_hours":11.3,"date":"2028-01-12","moon_free_dark_hours":0.0,"moon_illumination":99,"moon_separation":94.3,"score":null,"score_astronomy":75,"score_weather":null,"transit_alt":89.6,"transit_local":"17:40","verdict":"unknown","weather_source":"none","weekday":"Wed"},{"best_hours":4.42,"best_label":"good","best_window":"18:55\u201323:20","dark_hours":11.28,"date":"2028-01-13","moon_free_dark_hours":0.23,"moon_illumination":95,"moon_separation":107.6,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"17:35","verdict":"unknown","weather_source":"none","weekday":"Thu"},{"best_hours":4.58,"best_label":"good","best_window":"18:55\u201323:30","dark_hours":11.26,"date":"2028-01-14","moon_free_dark_hours":1.55,"moon_illumination":89,"moon_separation":120.4,"score":null,"score_astronomy":100,"score_weather":null,"transit_alt":89.7,"transit_local":"17:30","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":"2027-12-16","target":{"common_name":"Andromeda Galaxy","dec":41.26875,"morphology":"SA(s)b","name":"M 31","ra":10.68470833,"simbad_url":"https://simbad.cds.unistra.fr/simbad/sim-id?Ident=M31","source":"sesame","type":"AGN","type_text":"galaxy with an active nucleus","vmag":3.44}}