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 North America Nebula: 03-11 (35), 03-08 (34), 03-09 (34), 03-10 (34), 03-07 (32) — by astronomy; check the weather when the night is within four days.

2041-02-10astronomy score per night — click a bar for that night2041-03-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-02-10 Sun	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 11:55	10.43	78%	96.4°
2041-02-11 Mon	12	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.39	85%	101.8°
2041-02-12 Tue	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 11:45	10.35	91%	106.6°
2041-02-13 Wed	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.2° 11:40	10.31	96%	110.8°
2041-02-14 Thu	11	—	unknown	05:40–05:45 (good, 0.08 h)	87.2° 11:40	10.27	99%	114.2°
2041-02-15 Fri	12	—	unknown	05:35–05:45 (good, 0.17 h)	87.2° 11:35	10.23	100%	116.6°
2041-02-16 Sat	13	—	unknown	05:30–05:45 (good, 0.25 h)	87.2° 11:30	10.19	99%	117.8°
2041-02-17 Sun	13	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.15	97%	117.7°
2041-02-18 Mon	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:20	10.11	93%	116.2°
2041-02-19 Tue	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:20	10.07	87%	113.6°
2041-02-20 Wed	15	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:15	10.03	80%	109.8°
2041-02-21 Thu	16	—	unknown	05:15–05:35 (good, 0.33 h)	87.2° 11:10	9.98	71%	105.2°
2041-02-22 Fri	17	—	unknown	05:10–05:35 (good, 0.42 h)	87.2° 11:05	9.94	61%	99.7°
2041-02-23 Sat	18	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:05	9.9	51%	93.8°
2041-02-24 Sun	19	—	unknown	04:55–05:30 (good, 0.58 h)	87.2° 11:00	9.85	40%	87.5°
2041-02-25 Mon	21	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 10:55	9.81	29%	81.1°
2041-02-26 Tue	24	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.77	20%	75.0°
2041-02-27 Wed	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.72	11%	69.5°
2041-02-28 Thu	27	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.68	5%	65.3°
2041-03-01 Fri	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.63	1%	62.7°
2041-03-02 Sat	29	—	unknown	04:20–05:25 (good, 1.08 h)	87.2° 10:35	9.58	0%	62.2°
2041-03-03 Sun	29	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.54	3%	63.7°
2041-03-04 Mon	30	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.49	8%	67.0°
2041-03-05 Tue	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.45	15%	71.6°
2041-03-06 Wed	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.4	23%	77.0°
2041-03-07 Thu	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.35	33%	82.9°
2041-03-08 Fri	34	—	unknown	03:55–05:15 (good, 1.33 h)	87.2° 10:10	9.3	43%	88.8°
2041-03-09 Sat	34	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:10	9.25	53%	94.6°
2041-03-10 Sun	34	—	unknown	03:50–05:10 (good, 1.33 h)	87.2° 10:05	9.21	62%	100.1°
2041-03-11 Mon	35	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:00	9.16	71%	105.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-02-10&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.