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: 03-10 (48), 03-11 (46), 03-12 (45), 03-13 (43), 03-14 (41) — by astronomy; check the weather when the night is within four days.

2048-03-10astronomy score per night — click a bar for that night2048-04-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-03-10 Tue	48	—	unknown	20:00–22:00 (good, 2.0 h)	42.9° 18:45	9.19	15%	131.7°
2048-03-11 Wed	46	—	unknown	20:00–22:00 (good, 2.0 h)	42.9° 18:40	9.14	8%	121.0°
2048-03-12 Thu	45	—	unknown	20:00–21:55 (good, 1.92 h)	42.9° 18:35	9.09	3%	109.8°
2048-03-13 Fri	43	—	unknown	20:00–21:50 (good, 1.83 h)	42.9° 18:30	9.04	1%	98.4°
2048-03-14 Sat	41	—	unknown	20:00–21:45 (good, 1.75 h)	42.9° 18:25	8.99	0%	87.2°
2048-03-15 Sun	39	—	unknown	20:05–21:40 (good, 1.58 h)	42.9° 18:25	8.94	2%	76.2°
2048-03-16 Mon	37	—	unknown	20:05–21:40 (good, 1.58 h)	42.9° 18:20	8.89	6%	65.5°
2048-03-17 Tue	33	—	unknown	20:05–21:30 (good, 1.42 h)	42.9° 18:15	8.84	11%	55.5°
2048-03-18 Wed	29	—	unknown	20:05–21:20 (good, 1.25 h)	42.9° 18:10	8.79	18%	46.2°
2048-03-19 Thu	23	—	unknown	20:10–21:10 (good, 1.0 h)	42.9° 18:05	8.74	25%	38.1°
2048-03-20 Fri	19	—	unknown	20:10–20:55 (good, 0.75 h)	42.9° 18:05	8.69	34%	32.1°
2048-03-21 Sat	14	—	unknown	20:10–21:45 (marginal, 1.58 h)	42.9° 18:00	8.64	43%	29.4°
2048-03-22 Sun	10	—	unknown	20:10–21:35 (marginal, 1.42 h)	42.9° 17:55	8.58	52%	30.9°
2048-03-23 Mon	8	—	unknown	20:15–21:20 (marginal, 1.08 h)	42.9° 17:50	8.53	62%	36.2°
2048-03-24 Tue	7	—	unknown	20:15–21:10 (marginal, 0.92 h)	42.9° 17:50	8.48	71%	44.2°
2048-03-25 Wed	7	—	unknown	20:15–21:05 (marginal, 0.83 h)	42.9° 17:45	8.42	80%	53.8°
2048-03-26 Thu	7	—	unknown	20:15–21:10 (marginal, 0.92 h)	42.9° 17:40	8.37	88%	64.5°
2048-03-27 Fri	8	—	unknown	20:20–21:10 (marginal, 0.83 h)	42.9° 17:35	8.32	94%	76.0°
2048-03-28 Sat	9	—	unknown	20:20–21:15 (marginal, 0.92 h)	42.9° 17:30	8.26	98%	88.1°
2048-03-29 Sun	11	—	unknown	20:45–22:20 (marginal, 1.58 h)	42.9° 18:30	8.21	100%	100.5°
2048-03-30 Mon	10	—	unknown	21:25–21:30 (good, 0.08 h)	42.9° 18:25	8.15	99%	113.0°
2048-03-31 Tue	12	—	unknown	21:25–21:40 (good, 0.25 h)	42.9° 18:20	8.1	95%	125.1°
2048-04-01 Wed	10	—	unknown	21:25–21:35 (good, 0.17 h)	42.9° 18:15	8.05	89%	136.3°
2048-04-02 Thu	9	—	unknown	21:25–21:30 (good, 0.08 h)	42.9° 18:10	7.99	80%	145.4°
2048-04-03 Fri	7	—	unknown	21:30–22:00 (marginal, 0.5 h)	42.9° 18:10	7.93	70%	150.4°
2048-04-04 Sat	6	—	unknown	21:30–21:55 (marginal, 0.42 h)	42.9° 18:05	7.88	59%	149.4°
2048-04-05 Sun	5	—	unknown	21:30–21:50 (marginal, 0.33 h)	42.9° 18:00	7.82	48%	143.2°
2048-04-06 Mon	4	—	unknown	21:30–21:45 (marginal, 0.25 h)	42.9° 17:55	7.77	37%	134.1°
2048-04-07 Tue	3	—	unknown	21:35–21:45 (marginal, 0.17 h)	42.9° 17:50	7.71	27%	123.7°
2048-04-08 Wed	3	—	unknown	21:00–21:10 (marginal, 0.17 h)	42.9° 17:50	7.65	18%	112.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-03-10&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.