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: 02-05 (93), 02-06 (93), 02-07 (93), 02-08 (93), 02-09 (93) — by astronomy; check the weather when the night is within four days.

2035-02-05astronomy score per night — click a bar for that night2035-03-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-02-05 Mon	93	—	unknown	00:00–05:55 (good, 5.92 h)	50.2° 03:50	10.63	6%	102.9°
2035-02-06 Tue	93	—	unknown	23:55–05:55 (good, 6.0 h)	50.2° 03:45	10.59	2%	115.3°
2035-02-07 Wed	93	—	unknown	23:55–05:55 (good, 6.0 h)	50.2° 03:40	10.56	0%	127.8°
2035-02-08 Thu	93	—	unknown	23:50–05:55 (good, 6.08 h)	50.2° 03:35	10.52	0%	140.6°
2035-02-09 Fri	93	—	unknown	23:45–05:50 (good, 6.08 h)	50.2° 03:30	10.48	3%	153.6°
2035-02-10 Sat	93	—	unknown	23:40–05:50 (good, 6.17 h)	50.2° 03:30	10.45	7%	166.8°
2035-02-11 Sun	93	—	unknown	23:35–05:50 (good, 6.25 h)	50.2° 03:25	10.41	14%	177.1°
2035-02-12 Mon	93	—	unknown	23:35–05:50 (good, 6.25 h)	50.2° 03:20	10.37	22%	165.5°
2035-02-13 Tue	93	—	unknown	23:30–05:45 (good, 6.25 h)	50.2° 03:15	10.33	32%	151.9°
2035-02-14 Wed	93	—	unknown	23:30–05:45 (good, 6.25 h)	50.2° 03:10	10.29	43%	138.0°
2035-02-15 Thu	93	—	unknown	23:25–05:45 (good, 6.33 h)	50.2° 03:10	10.25	54%	123.9°
2035-02-16 Fri	93	—	unknown	23:30–05:45 (good, 6.25 h)	50.2° 03:05	10.21	66%	109.8°
2035-02-17 Sat	93	—	unknown	23:40–05:40 (good, 6.0 h)	50.2° 03:00	10.17	76%	95.5°
2035-02-18 Sun	89	—	unknown	00:50–05:40 (good, 4.83 h)	50.2° 02:55	10.13	85%	81.2°
2035-02-19 Mon	84	—	unknown	03:05–05:40 (good, 2.58 h)	50.2° 02:55	10.09	92%	66.9°
2035-02-20 Tue	43	—	unknown	23:20–05:40 (marginal, 6.33 h)	50.2° 02:50	10.05	97%	52.7°
2035-02-21 Wed	27	—	unknown	01:25–05:35 (marginal, 4.17 h)	50.2° 02:45	10.01	100%	38.7°
2035-02-22 Thu	20	—	unknown	03:15–05:35 (marginal, 2.33 h)	50.2° 02:40	9.96	100%	25.0°
2035-02-23 Fri	20	—	unknown	02:50–05:35 (marginal, 2.75 h)	50.2° 02:35	9.92	97%	11.8°
2035-02-24 Sat	24	—	unknown	22:50–05:35 (marginal, 6.75 h)	50.2° 02:35	9.88	92%	3.3°
2035-02-25 Sun	34	—	unknown	22:30–05:30 (marginal, 7.0 h)	50.2° 02:30	9.83	86%	14.7°
2035-02-26 Mon	54	—	unknown	22:10–05:30 (marginal, 7.33 h)	50.2° 02:25	9.79	79%	27.1°
2035-02-27 Tue	83	—	unknown	22:35–02:00 (good, 3.42 h)	50.2° 02:20	9.75	70%	39.2°
2035-02-28 Wed	89	—	unknown	22:30–04:45 (good, 6.25 h)	50.2° 02:15	9.7	61%	51.2°
2035-03-01 Thu	92	—	unknown	22:25–05:25 (good, 7.0 h)	50.2° 02:15	9.66	52%	63.0°
2035-03-02 Fri	93	—	unknown	22:25–05:25 (good, 7.0 h)	50.2° 02:10	9.61	42%	74.8°
2035-03-03 Sat	93	—	unknown	22:20–05:20 (good, 7.0 h)	50.2° 02:05	9.56	33%	86.7°
2035-03-04 Sun	93	—	unknown	22:15–05:20 (good, 7.08 h)	50.2° 02:00	9.52	24%	98.7°
2035-03-05 Mon	93	—	unknown	22:10–05:20 (good, 7.17 h)	50.2° 02:00	9.47	17%	110.9°
2035-03-06 Tue	93	—	unknown	22:05–05:15 (good, 7.17 h)	50.2° 01:55	9.42	10%	123.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-02-05&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.