Rozhen Observation Calendar

Which nights are best for a target over the coming weeks. The astronomy mark (darkness × altitude × Moon) is computed for every night; the weather and the overall mark exist only where Open-Meteo has a forecast (the next four days) or ERA5 history (past nights) — the rest is honestly blank.

Best nights for HD 189733: 10-22 (100), 10-23 (97), 10-24 (91), 11-08 (91), 11-09 (91) — by astronomy; check the weather when the night is within four days.

2036-10-22astronomy score per night — click a bar for that night2036-11-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-10-22 Wed	100	—	unknown	20:05–00:25 (good, 4.33 h)	71.1° 19:15	10.14	14%	61.9°
2036-10-23 Thu	97	—	unknown	20:05–00:20 (good, 4.25 h)	71.1° 19:15	10.18	21%	54.0°
2036-10-24 Fri	91	—	unknown	20:00–00:15 (good, 4.25 h)	71.1° 19:10	10.22	30%	47.6°
2036-10-25 Sat	80	—	unknown	20:00–00:10 (good, 4.17 h)	71.1° 19:05	10.26	39%	43.4°
2036-10-26 Sun	64	—	unknown	19:00–22:50 (good, 3.83 h)	71.1° 18:00	10.3	49%	41.6°
2036-10-27 Mon	53	—	unknown	18:55–22:35 (good, 3.67 h)	71.1° 17:55	10.34	58%	42.6°
2036-10-28 Tue	45	—	unknown	18:55–20:55 (good, 2.0 h)	71.1° 17:55	10.37	67%	46.1°
2036-10-29 Wed	40	—	unknown	18:55–20:00 (good, 1.08 h)	71.1° 17:50	10.41	76%	51.6°
2036-10-30 Thu	39	—	unknown	18:55–19:45 (good, 0.83 h)	71.1° 17:45	10.45	83%	58.7°
2036-10-31 Fri	39	—	unknown	18:55–19:50 (good, 0.92 h)	71.1° 17:40	10.49	90%	66.8°
2036-11-01 Sat	43	—	unknown	18:50–20:15 (good, 1.42 h)	71.1° 17:35	10.52	95%	75.7°
2036-11-02 Sun	49	—	unknown	18:50–20:55 (good, 2.08 h)	71.1° 17:35	10.56	98%	85.1°
2036-11-03 Mon	58	—	unknown	18:50–21:35 (good, 2.75 h)	71.1° 17:30	10.59	100%	94.8°
2036-11-04 Tue	67	—	unknown	18:50–22:10 (good, 3.33 h)	71.1° 17:25	10.63	99%	104.6°
2036-11-05 Wed	77	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:20	10.66	96%	114.2°
2036-11-06 Thu	89	—	unknown	18:45–22:15 (good, 3.5 h)	71.1° 17:20	10.7	90%	123.1°
2036-11-07 Fri	89	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:15	10.73	83%	130.7°
2036-11-08 Sat	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:10	10.76	73%	136.1°
2036-11-09 Sun	91	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:05	10.79	63%	138.3°
2036-11-10 Mon	90	—	unknown	18:45–22:10 (good, 3.42 h)	71.1° 17:00	10.83	52%	136.7°
2036-11-11 Tue	89	—	unknown	18:40–22:05 (good, 3.42 h)	71.1° 17:00	10.86	40%	131.6°
2036-11-12 Wed	88	—	unknown	18:40–22:00 (good, 3.33 h)	71.1° 16:55	10.89	29%	124.1°
2036-11-13 Thu	86	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:50	10.92	20%	115.1°
2036-11-14 Fri	85	—	unknown	18:40–21:55 (good, 3.25 h)	71.1° 16:45	10.95	12%	105.2°
2036-11-15 Sat	83	—	unknown	18:40–21:50 (good, 3.17 h)	71.1° 16:40	10.98	5%	94.9°
2036-11-16 Sun	81	—	unknown	18:40–21:45 (good, 3.08 h)	71.1° 16:40	11.0	2%	84.7°
2036-11-17 Mon	79	—	unknown	18:40–21:40 (good, 3.0 h)	71.1° 16:35	11.03	0%	74.7°
2036-11-18 Tue	79	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:30	11.06	1%	65.3°
2036-11-19 Wed	77	—	unknown	18:35–21:35 (good, 3.0 h)	71.1° 16:25	11.08	4%	57.0°
2036-11-20 Thu	72	—	unknown	18:35–21:30 (good, 2.92 h)	71.1° 16:25	11.11	9%	49.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-10-22&days=30"
curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&days=30&format=csv" -o m31-calendar.csv

One row per night: score_astronomy always, score_weather / score only where a forecast or history exists (null otherwise, with weather_source saying which), best window, dark hours, Moon illumination and separation, transit. 7–60 nights. Errors: 400 with invalid_date or target_unresolved. Results are cached for six hours; calculation version 2026-10-10.1.