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: 08-25 (100), 08-26 (100), 08-27 (100), 08-28 (100), 08-29 (100) — by astronomy; check the weather when the night is within four days.

2033-08-25astronomy score per night — click a bar for that night2033-09-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-08-25 Thu	100	—	unknown	21:50–04:10 (good, 6.33 h)	71.1° 23:05	7.23	1%	129.0°
2033-08-26 Fri	100	—	unknown	21:45–04:10 (good, 6.42 h)	71.1° 23:00	7.29	4%	121.0°
2033-08-27 Sat	100	—	unknown	21:45–04:05 (good, 6.33 h)	71.1° 23:00	7.35	8%	112.4°
2033-08-28 Sun	100	—	unknown	21:45–04:00 (good, 6.25 h)	71.1° 22:55	7.4	14%	103.3°
2033-08-29 Mon	100	—	unknown	21:40–03:55 (good, 6.25 h)	71.1° 22:50	7.46	21%	94.0°
2033-08-30 Tue	100	—	unknown	21:40–03:50 (good, 6.17 h)	71.1° 22:45	7.52	30%	84.5°
2033-08-31 Wed	100	—	unknown	21:35–03:50 (good, 6.25 h)	71.1° 22:40	7.57	39%	75.1°
2033-09-01 Thu	100	—	unknown	21:35–03:45 (good, 6.17 h)	71.1° 22:40	7.63	48%	65.8°
2033-09-02 Fri	98	—	unknown	21:35–03:40 (good, 6.08 h)	71.1° 22:35	7.68	58%	56.8°
2033-09-03 Sat	92	—	unknown	21:30–03:35 (good, 6.08 h)	71.1° 22:30	7.74	68%	48.6°
2033-09-04 Sun	84	—	unknown	23:10–03:35 (good, 4.42 h)	71.1° 22:25	7.79	78%	41.9°
2033-09-05 Mon	47	—	unknown	21:25–03:55 (marginal, 6.5 h)	71.1° 22:20	7.85	86%	37.9°
2033-09-06 Tue	37	—	unknown	21:25–03:35 (marginal, 6.17 h)	71.1° 22:20	7.9	93%	38.1°
2033-09-07 Wed	35	—	unknown	21:25–03:20 (marginal, 5.92 h)	71.1° 22:15	7.96	98%	42.7°
2033-09-08 Thu	41	—	unknown	21:20–03:15 (marginal, 5.92 h)	71.1° 22:10	8.01	100%	50.8°
2033-09-09 Fri	53	—	unknown	21:20–22:05 (good, 0.75 h)	71.1° 22:05	8.07	99%	60.9°
2033-09-10 Sat	71	—	unknown	21:15–00:15 (good, 3.0 h)	71.1° 22:05	8.12	95%	72.3°
2033-09-11 Sun	81	—	unknown	21:15–01:35 (good, 4.33 h)	71.1° 22:00	8.18	88%	84.0°
2033-09-12 Mon	100	—	unknown	21:15–02:35 (good, 5.33 h)	71.1° 21:55	8.23	80%	95.7°
2033-09-13 Tue	100	—	unknown	21:10–02:45 (good, 5.58 h)	71.1° 21:50	8.28	70%	106.9°
2033-09-14 Wed	100	—	unknown	21:10–02:45 (good, 5.58 h)	71.1° 21:45	8.34	59%	117.5°
2033-09-15 Thu	100	—	unknown	21:05–02:45 (good, 5.67 h)	71.1° 21:45	8.39	48%	126.9°
2033-09-16 Fri	100	—	unknown	21:05–02:40 (good, 5.58 h)	71.1° 21:40	8.44	37%	134.7°
2033-09-17 Sat	100	—	unknown	21:05–02:40 (good, 5.58 h)	71.1° 21:35	8.49	28%	140.1°
2033-09-18 Sun	100	—	unknown	21:00–02:40 (good, 5.67 h)	71.1° 21:30	8.54	19%	142.5°
2033-09-19 Mon	100	—	unknown	21:00–02:35 (good, 5.58 h)	71.1° 21:25	8.6	12%	141.5°
2033-09-20 Tue	100	—	unknown	21:00–02:30 (good, 5.5 h)	71.1° 21:25	8.65	6%	137.3°
2033-09-21 Wed	100	—	unknown	20:55–02:25 (good, 5.5 h)	71.1° 21:20	8.7	2%	131.0°
2033-09-22 Thu	100	—	unknown	20:55–02:20 (good, 5.42 h)	71.1° 21:15	8.75	0%	123.3°
2033-09-23 Fri	100	—	unknown	20:50–02:20 (good, 5.5 h)	71.1° 21:10	8.8	0%	114.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-08-25&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.