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: 10-26 (89), 10-27 (89), 10-28 (89), 10-29 (89), 10-30 (89) — by astronomy; check the weather when the night is within four days.

2046-10-10astronomy score per night — click a bar for that night2046-11-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-10-10 Wed	75	—	unknown	02:40–06:00 (good, 3.33 h)	42.9° 05:40	9.61	86%	108.3°
2046-10-11 Thu	70	—	unknown	02:45–06:00 (good, 3.25 h)	42.9° 05:35	9.65	92%	98.3°
2046-10-12 Fri	64	—	unknown	03:20–06:00 (good, 2.67 h)	42.9° 05:30	9.7	96%	88.3°
2046-10-13 Sat	41	—	unknown	04:45–06:00 (good, 1.25 h)	42.9° 05:25	9.74	99%	78.2°
2046-10-14 Sun	31	—	unknown	02:05–06:05 (marginal, 4.0 h)	42.9° 05:25	9.78	100%	68.3°
2046-10-15 Mon	23	—	unknown	02:20–06:05 (marginal, 3.75 h)	42.9° 05:20	9.83	99%	58.7°
2046-10-16 Tue	17	—	unknown	02:30–06:05 (marginal, 3.58 h)	42.9° 05:15	9.87	96%	49.6°
2046-10-17 Wed	14	—	unknown	03:30–06:05 (marginal, 2.58 h)	42.9° 05:10	9.91	92%	41.4°
2046-10-18 Thu	13	—	unknown	02:25–06:10 (marginal, 3.75 h)	42.9° 05:10	9.96	86%	35.0°
2046-10-19 Fri	15	—	unknown	02:00–06:10 (marginal, 4.17 h)	42.9° 05:05	10.0	78%	31.8°
2046-10-20 Sat	23	—	unknown	01:35–06:10 (marginal, 4.58 h)	42.9° 05:00	10.04	70%	32.8°
2046-10-21 Sun	36	—	unknown	01:15–06:10 (marginal, 4.92 h)	42.9° 04:55	10.08	60%	37.9°
2046-10-22 Mon	51	—	unknown	02:05–06:00 (good, 3.92 h)	42.9° 04:50	10.12	49%	46.0°
2046-10-23 Tue	68	—	unknown	01:50–06:15 (good, 4.42 h)	42.9° 04:50	10.16	38%	56.0°
2046-10-24 Wed	83	—	unknown	01:30–06:15 (good, 4.75 h)	42.9° 04:45	10.2	28%	67.3°
2046-10-25 Thu	88	—	unknown	01:25–06:15 (good, 4.83 h)	42.9° 04:40	10.24	18%	79.4°
2046-10-26 Fri	89	—	unknown	01:20–06:15 (good, 4.92 h)	42.9° 04:35	10.28	10%	92.0°
2046-10-27 Sat	89	—	unknown	01:20–05:15 (good, 4.92 h)	42.9° 03:30	10.32	4%	104.7°
2046-10-28 Sun	89	—	unknown	00:15–05:20 (good, 5.08 h)	42.9° 03:30	10.36	1%	117.2°
2046-10-29 Mon	89	—	unknown	00:10–05:20 (good, 5.17 h)	42.9° 03:25	10.4	0%	129.0°
2046-10-30 Tue	89	—	unknown	00:05–05:20 (good, 5.25 h)	42.9° 03:20	10.43	3%	139.0°
2046-10-31 Wed	89	—	unknown	00:00–05:20 (good, 5.33 h)	42.9° 03:15	10.47	8%	146.1°
2046-11-01 Thu	89	—	unknown	00:00–05:25 (good, 5.42 h)	42.9° 03:15	10.51	16%	148.5°
2046-11-02 Fri	89	—	unknown	23:55–05:25 (good, 5.5 h)	42.9° 03:10	10.54	25%	145.6°
2046-11-03 Sat	89	—	unknown	23:50–05:25 (good, 5.58 h)	42.9° 03:05	10.58	34%	139.0°
2046-11-04 Sun	89	—	unknown	23:45–05:25 (good, 5.67 h)	42.9° 03:00	10.61	44%	130.5°
2046-11-05 Mon	89	—	unknown	23:45–05:25 (good, 5.67 h)	42.9° 02:55	10.65	54%	121.0°
2046-11-06 Tue	89	—	unknown	23:50–05:30 (good, 5.67 h)	42.9° 02:55	10.68	63%	111.2°
2046-11-07 Wed	89	—	unknown	23:50–05:30 (good, 5.67 h)	42.9° 02:50	10.72	72%	101.2°
2046-11-08 Thu	89	—	unknown	00:00–05:30 (good, 5.5 h)	42.9° 02:45	10.75	80%	91.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-10-10&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.