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

2035-02-25astronomy score per night — click a bar for that night2035-03-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2035-03-07 Wed	93	—	unknown	22:05–05:15 (good, 7.17 h)	50.2° 01:50	9.38	5%	136.1°
2035-03-08 Thu	93	—	unknown	22:00–05:15 (good, 7.25 h)	50.2° 01:45	9.33	1%	149.1°
2035-03-09 Fri	93	—	unknown	21:55–05:10 (good, 7.25 h)	50.2° 01:40	9.28	0%	162.4°
2035-03-10 Sat	93	—	unknown	21:50–05:10 (good, 7.33 h)	50.2° 01:40	9.23	1%	175.4°
2035-03-11 Sun	93	—	unknown	21:45–05:10 (good, 7.42 h)	50.2° 01:35	9.18	5%	169.3°
2035-03-12 Mon	93	—	unknown	21:45–05:05 (good, 7.33 h)	50.2° 01:30	9.13	11%	155.5°
2035-03-13 Tue	93	—	unknown	21:40–05:05 (good, 7.42 h)	50.2° 01:25	9.09	19%	141.4°
2035-03-14 Wed	93	—	unknown	21:40–05:05 (good, 7.42 h)	50.2° 01:20	9.04	29%	127.2°
2035-03-15 Thu	93	—	unknown	21:35–05:00 (good, 7.42 h)	50.2° 01:20	8.99	40%	113.0°
2035-03-16 Fri	93	—	unknown	21:40–05:00 (good, 7.33 h)	50.2° 01:15	8.94	51%	98.9°
2035-03-17 Sat	90	—	unknown	21:50–05:00 (good, 7.17 h)	50.2° 01:10	8.88	62%	84.8°
2035-03-18 Sun	86	—	unknown	23:10–04:55 (good, 5.75 h)	50.2° 01:05	8.83	73%	70.8°
2035-03-19 Mon	81	—	unknown	02:10–04:55 (good, 2.75 h)	50.2° 01:05	8.78	82%	57.0°
2035-03-20 Tue	45	—	unknown	21:30–04:55 (marginal, 7.42 h)	50.2° 01:00	8.73	90%	43.3°
2035-03-21 Wed	28	—	unknown	00:30–04:50 (marginal, 4.33 h)	50.2° 00:55	8.68	96%	29.8°
2035-03-22 Thu	23	—	unknown	01:30–04:45 (marginal, 3.25 h)	50.2° 00:50	8.63	99%	16.5°
2035-03-23 Fri	21	—	unknown	02:10–04:30 (marginal, 2.33 h)	50.2° 00:45	8.58	100%	4.2°
2035-03-24 Sat	24	—	unknown	21:00–05:15 (marginal, 7.25 h)	50.2° 00:45	8.52	99%	10.1°
2035-03-25 Sun	33	—	unknown	21:40–05:15 (marginal, 7.58 h)	50.2° 01:40	8.47	96%	22.5°
2035-03-26 Mon	78	—	unknown	21:50–22:25 (good, 0.58 h)	50.2° 01:35	8.42	91%	34.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-02-25&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.