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: 10-13 (84), 10-14 (84), 10-12 (82), 10-11 (81), 10-10 (80) — by astronomy; check the weather when the night is within four days.

2032-09-18astronomy score per night — click a bar for that night2032-10-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-09-18 Sat	25	—	unknown	04:20–05:35 (good, 1.25 h)	42.9° 07:05	8.56	100%	94.4°
2032-09-19 Sun	19	—	unknown	03:25–05:35 (marginal, 2.17 h)	42.9° 07:00	8.61	100%	80.6°
2032-09-20 Mon	14	—	unknown	03:35–05:35 (marginal, 2.0 h)	42.9° 06:55	8.66	97%	67.2°
2032-09-21 Tue	11	—	unknown	03:45–05:40 (marginal, 1.92 h)	42.9° 06:50	8.71	91%	54.4°
2032-09-22 Wed	10	—	unknown	03:45–05:40 (marginal, 1.92 h)	42.9° 06:50	8.76	83%	42.6°
2032-09-23 Thu	10	—	unknown	03:35–05:40 (marginal, 2.08 h)	42.9° 06:45	8.81	74%	32.7°
2032-09-24 Fri	14	—	unknown	03:15–05:40 (marginal, 2.42 h)	42.9° 06:40	8.86	65%	26.0°
2032-09-25 Sat	20	—	unknown	03:00–05:45 (marginal, 2.75 h)	42.9° 06:35	8.91	55%	24.7°
2032-09-26 Sun	27	—	unknown	02:45–05:45 (marginal, 3.0 h)	42.9° 06:30	8.96	45%	29.0°
2032-09-27 Mon	36	—	unknown	03:35–05:45 (good, 2.17 h)	42.9° 06:30	9.01	35%	36.7°
2032-09-28 Tue	44	—	unknown	03:20–05:45 (good, 2.42 h)	42.9° 06:25	9.06	26%	45.9°
2032-09-29 Wed	52	—	unknown	03:05–05:45 (good, 2.67 h)	42.9° 06:20	9.11	18%	56.0°
2032-09-30 Thu	59	—	unknown	03:00–05:50 (good, 2.83 h)	42.9° 06:15	9.16	12%	66.4°
2032-10-01 Fri	64	—	unknown	03:00–05:50 (good, 2.83 h)	42.9° 06:10	9.21	6%	77.0°
2032-10-02 Sat	66	—	unknown	02:55–05:50 (good, 2.92 h)	42.9° 06:10	9.25	2%	87.8°
2032-10-03 Sun	67	—	unknown	02:50–05:50 (good, 3.0 h)	42.9° 06:05	9.3	0%	98.7°
2032-10-04 Mon	70	—	unknown	02:45–05:55 (good, 3.17 h)	42.9° 06:00	9.35	0%	109.6°
2032-10-05 Tue	71	—	unknown	02:40–05:55 (good, 3.25 h)	42.9° 05:55	9.39	2%	120.5°
2032-10-06 Wed	72	—	unknown	02:40–05:55 (good, 3.25 h)	42.9° 05:55	9.44	5%	131.2°
2032-10-07 Thu	74	—	unknown	02:35–05:55 (good, 3.33 h)	42.9° 05:50	9.49	11%	141.2°
2032-10-08 Fri	76	—	unknown	02:30–05:55 (good, 3.42 h)	42.9° 05:45	9.53	18%	149.8°
2032-10-09 Sat	78	—	unknown	02:25–06:00 (good, 3.58 h)	42.9° 05:40	9.58	27%	155.0°
2032-10-10 Sun	80	—	unknown	02:25–06:00 (good, 3.58 h)	42.9° 05:35	9.62	37%	154.4°
2032-10-11 Mon	81	—	unknown	02:20–06:00 (good, 3.67 h)	42.9° 05:35	9.67	47%	147.8°
2032-10-12 Tue	82	—	unknown	02:15–06:00 (good, 3.75 h)	42.9° 05:30	9.71	59%	137.8°
2032-10-13 Wed	84	—	unknown	02:10–06:05 (good, 3.92 h)	42.9° 05:25	9.76	70%	126.1°
2032-10-14 Thu	84	—	unknown	02:20–06:05 (good, 3.75 h)	42.9° 05:20	9.8	80%	113.4°
2032-10-15 Fri	79	—	unknown	02:25–06:05 (good, 3.67 h)	42.9° 05:15	9.84	88%	100.2°
2032-10-16 Sat	70	—	unknown	03:05–06:05 (good, 3.0 h)	42.9° 05:15	9.89	95%	86.7°
2032-10-17 Sun	41	—	unknown	05:10–06:05 (good, 0.92 h)	42.9° 05:10	9.93	99%	73.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-09-18&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.