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 3C 273: 04-01 (93), 04-02 (93), 04-03 (93), 04-04 (93), 04-18 (93) — by astronomy; check the weather when the night is within four days.

2033-04-01astronomy score per night — click a bar for that night2033-04-30

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-04-01 Fri	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.2° 01:10	8.07	7%	142.8°
2033-04-02 Sat	93	—	unknown	21:25–05:00 (good, 7.58 h)	50.2° 01:05	8.01	14%	128.5°
2033-04-03 Sun	93	—	unknown	21:30–04:55 (good, 7.42 h)	50.2° 01:00	7.96	23%	114.6°
2033-04-04 Mon	93	—	unknown	21:30–04:50 (good, 7.33 h)	50.2° 01:00	7.9	33%	101.2°
2033-04-05 Tue	91	—	unknown	21:30–04:45 (good, 7.25 h)	50.2° 00:55	7.84	43%	88.2°
2033-04-06 Wed	88	—	unknown	21:30–04:40 (good, 7.17 h)	50.2° 00:50	7.79	53%	75.6°
2033-04-07 Thu	84	—	unknown	22:40–04:40 (good, 6.0 h)	50.2° 00:45	7.73	63%	63.3°
2033-04-08 Fri	80	—	unknown	01:05–04:35 (good, 3.5 h)	50.2° 00:40	7.68	72%	51.3°
2033-04-09 Sat	53	—	unknown	21:35–05:00 (marginal, 7.42 h)	50.2° 00:40	7.62	80%	39.4°
2033-04-10 Sun	34	—	unknown	21:40–04:45 (marginal, 7.08 h)	50.2° 00:35	7.56	87%	27.8°
2033-04-11 Mon	27	—	unknown	21:40–04:30 (marginal, 6.83 h)	50.2° 00:30	7.51	93%	16.5°
2033-04-12 Tue	23	—	unknown	21:40–04:15 (marginal, 6.58 h)	50.2° 00:25	7.45	97%	7.1°
2033-04-13 Wed	21	—	unknown	21:40–04:05 (marginal, 6.42 h)	50.2° 00:20	7.39	99%	10.4°
2033-04-14 Thu	25	—	unknown	21:45–03:50 (marginal, 6.08 h)	50.2° 00:20	7.33	100%	21.2°
2033-04-15 Fri	33	—	unknown	21:45–03:50 (marginal, 6.08 h)	50.2° 00:15	7.28	99%	32.9°
2033-04-16 Sat	76	—	unknown	21:45–21:55 (good, 0.17 h)	50.2° 00:10	7.22	96%	45.0°
2033-04-17 Sun	91	—	unknown	21:50–00:40 (good, 2.83 h)	50.2° 00:05	7.16	91%	57.2°
2033-04-18 Mon	93	—	unknown	21:50–02:30 (good, 4.67 h)	50.2° 00:05	7.1	84%	69.7°
2033-04-19 Tue	93	—	unknown	21:50–03:25 (good, 5.58 h)	50.2° 00:00	7.04	76%	82.4°
2033-04-20 Wed	93	—	unknown	21:50–03:30 (good, 5.67 h)	50.2° 23:55	6.99	67%	95.3°
2033-04-21 Thu	93	—	unknown	21:55–03:35 (good, 5.67 h)	50.2° 23:50	6.93	56%	108.5°
2033-04-22 Fri	93	—	unknown	21:55–03:35 (good, 5.67 h)	50.2° 23:45	6.87	45%	122.1°
2033-04-23 Sat	93	—	unknown	21:55–03:35 (good, 5.67 h)	50.2° 23:45	6.81	34%	135.9°
2033-04-24 Sun	93	—	unknown	22:00–03:30 (good, 5.5 h)	50.2° 23:40	6.75	24%	150.0°
2033-04-25 Mon	93	—	unknown	22:00–03:25 (good, 5.42 h)	50.2° 23:35	6.69	14%	164.1°
2033-04-26 Tue	93	—	unknown	22:00–03:25 (good, 5.42 h)	50.2° 23:30	6.64	7%	173.9°
2033-04-27 Wed	93	—	unknown	22:05–03:20 (good, 5.25 h)	50.2° 23:25	6.58	2%	163.7°
2033-04-28 Thu	93	—	unknown	22:05–03:15 (good, 5.17 h)	50.2° 23:25	6.52	0%	149.4°
2033-04-29 Fri	93	—	unknown	22:05–03:10 (good, 5.08 h)	50.2° 23:20	6.46	1%	134.9°
2033-04-30 Sat	93	—	unknown	22:10–03:05 (good, 4.92 h)	50.2° 23:15	6.4	5%	120.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-04-01&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.