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: 09-16 (37), 09-15 (36), 09-14 (35), 09-13 (33), 09-12 (31) — by astronomy; check the weather when the night is within four days.

2032-08-26astronomy score per night — click a bar for that night2032-09-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-08-26 Thu	2	—	unknown	—	42.9° 08:35	7.3	59%	38.8°
2032-08-27 Fri	2	—	unknown	04:55–05:05 (marginal, 0.17 h)	42.9° 08:30	7.36	49%	30.1°
2032-08-28 Sat	4	—	unknown	04:40–05:05 (marginal, 0.42 h)	42.9° 08:25	7.42	39%	25.2°
2032-08-29 Sun	6	—	unknown	04:35–05:10 (marginal, 0.58 h)	42.9° 08:20	7.47	29%	25.6°
2032-08-30 Mon	7	—	unknown	04:35–05:10 (marginal, 0.58 h)	42.9° 08:20	7.53	21%	31.0°
2032-08-31 Tue	9	—	unknown	05:05–05:10 (good, 0.08 h)	42.9° 08:15	7.59	14%	39.2°
2032-09-01 Wed	13	—	unknown	05:00–05:15 (good, 0.25 h)	42.9° 08:10	7.64	8%	48.7°
2032-09-02 Thu	15	—	unknown	04:50–05:15 (good, 0.42 h)	42.9° 08:05	7.7	4%	58.8°
2032-09-03 Fri	17	—	unknown	04:50–05:15 (good, 0.42 h)	42.9° 08:00	7.75	1%	69.2°
2032-09-04 Sat	18	—	unknown	04:45–05:15 (good, 0.5 h)	42.9° 08:00	7.81	0%	79.9°
2032-09-05 Sun	21	—	unknown	04:40–05:20 (good, 0.67 h)	42.9° 07:55	7.86	1%	90.7°
2032-09-06 Mon	22	—	unknown	04:35–05:20 (good, 0.75 h)	42.9° 07:50	7.92	4%	101.5°
2032-09-07 Tue	24	—	unknown	04:35–05:20 (good, 0.75 h)	42.9° 07:45	7.97	8%	112.4°
2032-09-08 Wed	24	—	unknown	04:30–05:20 (good, 0.83 h)	42.9° 07:45	8.03	14%	123.1°
2032-09-09 Thu	27	—	unknown	04:25–05:25 (good, 1.0 h)	42.9° 07:40	8.08	22%	133.6°
2032-09-10 Fri	28	—	unknown	04:20–05:25 (good, 1.08 h)	42.9° 07:35	8.14	31%	143.4°
2032-09-11 Sat	30	—	unknown	04:15–05:25 (good, 1.17 h)	42.9° 07:30	8.19	41%	151.4°
2032-09-12 Sun	31	—	unknown	04:15–05:25 (good, 1.17 h)	42.9° 07:25	8.24	52%	155.4°
2032-09-13 Mon	33	—	unknown	04:10–05:30 (good, 1.33 h)	42.9° 07:25	8.3	62%	153.0°
2032-09-14 Tue	35	—	unknown	04:05–05:30 (good, 1.42 h)	42.9° 07:20	8.35	73%	145.0°
2032-09-15 Wed	36	—	unknown	04:00–05:30 (good, 1.5 h)	42.9° 07:15	8.4	83%	134.0°
2032-09-16 Thu	37	—	unknown	04:05–05:30 (good, 1.42 h)	42.9° 07:10	8.45	91%	121.5°
2032-09-17 Fri	31	—	unknown	04:10–05:35 (good, 1.42 h)	42.9° 07:05	8.51	97%	108.1°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-08-26&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.