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 Great Orion Nebula: 03-02 (59), 03-03 (52), 03-04 (42), 03-16 (38), 03-15 (37) — by astronomy; check the weather when the night is within four days.

2044-03-02astronomy score per night — click a bar for that night2044-03-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-03-02 Wed	59	—	unknown	19:50–22:35 (good, 2.75 h)	42.9° 19:15	9.57	11%	66.7°
2044-03-03 Thu	52	—	unknown	19:50–22:25 (good, 2.58 h)	42.9° 19:10	9.53	19%	56.0°
2044-03-04 Fri	42	—	unknown	19:50–22:10 (good, 2.33 h)	42.9° 19:05	9.48	28%	46.3°
2044-03-05 Sat	32	—	unknown	19:50–21:55 (good, 2.08 h)	42.9° 19:00	9.43	39%	38.6°
2044-03-06 Sun	23	—	unknown	19:55–22:45 (marginal, 2.83 h)	42.9° 19:00	9.38	51%	34.3°
2044-03-07 Mon	16	—	unknown	19:55–22:25 (marginal, 2.5 h)	42.9° 18:55	9.34	62%	34.9°
2044-03-08 Tue	12	—	unknown	19:55–22:10 (marginal, 2.25 h)	42.9° 18:50	9.29	73%	40.1°
2044-03-09 Wed	11	—	unknown	19:55–22:00 (marginal, 2.08 h)	42.9° 18:45	9.24	82%	48.5°
2044-03-10 Thu	12	—	unknown	19:55–22:00 (marginal, 2.08 h)	42.9° 18:40	9.19	90%	58.6°
2044-03-11 Fri	15	—	unknown	20:00–22:05 (marginal, 2.08 h)	42.9° 18:40	9.14	96%	69.5°
2044-03-12 Sat	20	—	unknown	20:00–22:10 (marginal, 2.17 h)	42.9° 18:35	9.09	99%	80.7°
2044-03-13 Sun	24	—	unknown	20:00–21:00 (good, 1.0 h)	42.9° 18:30	9.04	100%	91.9°
2044-03-14 Mon	29	—	unknown	20:00–21:25 (good, 1.42 h)	42.9° 18:25	8.99	99%	102.9°
2044-03-15 Tue	37	—	unknown	20:05–21:30 (good, 1.42 h)	42.9° 18:25	8.94	95%	113.3°
2044-03-16 Wed	38	—	unknown	20:05–21:40 (good, 1.58 h)	42.9° 18:20	8.89	90%	123.1°
2044-03-17 Thu	36	—	unknown	20:05–21:35 (good, 1.5 h)	42.9° 18:15	8.84	83%	131.8°
2044-03-18 Fri	35	—	unknown	20:05–21:30 (good, 1.42 h)	42.9° 18:10	8.79	75%	139.1°
2044-03-19 Sat	32	—	unknown	20:10–21:25 (good, 1.25 h)	42.9° 18:05	8.74	66%	144.1°
2044-03-20 Sun	31	—	unknown	20:10–21:20 (good, 1.17 h)	42.9° 18:05	8.69	57%	146.1°
2044-03-21 Mon	29	—	unknown	20:10–21:20 (good, 1.17 h)	42.9° 18:00	8.64	48%	144.5°
2044-03-22 Tue	28	—	unknown	20:10–21:15 (good, 1.08 h)	42.9° 17:55	8.58	38%	139.7°
2044-03-23 Wed	26	—	unknown	20:15–21:10 (good, 0.92 h)	42.9° 17:50	8.53	29%	132.7°
2044-03-24 Thu	25	—	unknown	20:15–21:05 (good, 0.83 h)	42.9° 17:45	8.48	21%	124.1°
2044-03-25 Fri	23	—	unknown	20:15–21:05 (good, 0.83 h)	42.9° 17:45	8.43	13%	114.4°
2044-03-26 Sat	22	—	unknown	20:15–21:00 (good, 0.75 h)	42.9° 17:40	8.37	7%	104.0°
2044-03-27 Sun	19	—	unknown	21:20–21:55 (good, 0.58 h)	42.9° 18:35	8.32	3%	93.1°
2044-03-28 Mon	17	—	unknown	21:20–21:50 (good, 0.5 h)	42.9° 18:30	8.27	0%	81.8°
2044-03-29 Tue	16	—	unknown	21:20–21:45 (good, 0.42 h)	42.9° 18:30	8.21	0%	70.4°
2044-03-30 Wed	13	—	unknown	21:25–21:45 (good, 0.33 h)	42.9° 18:25	8.16	3%	59.3°
2044-03-31 Thu	11	—	unknown	21:25–21:35 (good, 0.17 h)	42.9° 18:20	8.1	8%	48.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-03-02&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.