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: 01-08 (93), 01-09 (93), 01-10 (93), 01-11 (93), 01-12 (93) — by astronomy; check the weather when the night is within four days.

2035-01-08astronomy score per night — click a bar for that night2035-02-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-08 Mon	93	—	unknown	01:50–06:10 (good, 4.33 h)	50.2° 05:40	11.36	1%	94.5°
2035-01-09 Tue	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:35	11.34	0%	106.6°
2035-01-10 Wed	93	—	unknown	01:45–06:10 (good, 4.42 h)	50.2° 05:30	11.33	2%	118.9°
2035-01-11 Thu	93	—	unknown	01:40–06:10 (good, 4.5 h)	50.2° 05:25	11.31	5%	131.4°
2035-01-12 Fri	93	—	unknown	01:35–06:10 (good, 4.58 h)	50.2° 05:20	11.29	11%	144.1°
2035-01-13 Sat	93	—	unknown	01:30–06:10 (good, 4.67 h)	50.2° 05:20	11.27	18%	156.9°
2035-01-14 Sun	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:15	11.25	26%	169.8°
2035-01-15 Mon	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 05:10	11.23	36%	175.4°
2035-01-16 Tue	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:05	11.21	47%	162.6°
2035-01-17 Wed	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:00	11.18	58%	148.8°
2035-01-18 Thu	93	—	unknown	01:20–06:10 (good, 4.83 h)	50.2° 05:00	11.16	69%	134.6°
2035-01-19 Fri	93	—	unknown	01:15–06:10 (good, 4.92 h)	50.2° 04:55	11.14	80%	120.2°
2035-01-20 Sat	93	—	unknown	01:25–06:10 (good, 4.75 h)	50.2° 04:50	11.11	88%	105.5°
2035-01-21 Sun	89	—	unknown	02:10–06:05 (good, 3.92 h)	50.2° 04:45	11.09	95%	90.7°
2035-01-22 Mon	54	—	unknown	04:00–06:05 (good, 2.08 h)	50.2° 04:45	11.06	99%	76.0°
2035-01-23 Tue	38	—	unknown	01:00–06:05 (marginal, 5.08 h)	50.2° 04:40	11.03	100%	61.3°
2035-01-24 Wed	26	—	unknown	01:15–06:05 (marginal, 4.83 h)	50.2° 04:35	11.01	98%	47.0°
2035-01-25 Thu	19	—	unknown	03:10–06:05 (marginal, 2.92 h)	50.2° 04:30	10.98	94%	33.0°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-08&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.