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: 02-02 (93), 02-03 (93), 02-04 (93), 02-05 (93), 02-06 (93) — by astronomy; check the weather when the night is within four days.

2035-01-26astronomy score per night — click a bar for that night2035-02-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-26 Fri	20	—	unknown	01:00–06:05 (marginal, 5.08 h)	50.2° 04:25	10.95	88%	19.4°
2035-01-27 Sat	26	—	unknown	00:30–06:05 (marginal, 5.58 h)	50.2° 04:25	10.92	81%	6.7°
2035-01-28 Sun	36	—	unknown	00:15–06:05 (marginal, 5.83 h)	50.2° 04:20	10.89	72%	7.4°
2035-01-29 Mon	49	—	unknown	00:00–06:00 (marginal, 6.0 h)	50.2° 04:15	10.86	63%	19.4°
2035-01-30 Tue	76	—	unknown	00:25–05:50 (good, 5.42 h)	50.2° 04:10	10.83	53%	31.5°
2035-01-31 Wed	86	—	unknown	00:20–06:00 (good, 5.67 h)	50.2° 04:05	10.8	44%	43.4°
2035-02-01 Thu	91	—	unknown	00:15–06:00 (good, 5.75 h)	50.2° 04:05	10.76	34%	55.2°
2035-02-02 Fri	93	—	unknown	00:15–06:00 (good, 5.75 h)	50.2° 04:00	10.73	26%	67.0°
2035-02-03 Sat	93	—	unknown	00:10–06:00 (good, 5.83 h)	50.2° 03:55	10.7	18%	78.8°
2035-02-04 Sun	93	—	unknown	00:05–05:55 (good, 5.83 h)	50.2° 03:50	10.66	11%	90.8°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-26&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.