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: 01-31 (89), 02-01 (89), 02-02 (89), 02-03 (89), 02-04 (89) — by astronomy; check the weather when the night is within four days.

2032-01-27astronomy score per night — click a bar for that night2032-02-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-01-27 Tue	31	—	unknown	19:10–00:25 (marginal, 5.25 h)	42.9° 21:30	10.93	100%	52.0°
2032-01-28 Wed	45	—	unknown	19:10–00:45 (marginal, 5.58 h)	42.9° 21:25	10.9	98%	62.1°
2032-01-29 Thu	79	—	unknown	19:10–21:50 (good, 2.67 h)	42.9° 21:25	10.87	95%	72.6°
2032-01-30 Fri	88	—	unknown	19:10–23:30 (good, 4.33 h)	42.9° 21:20	10.84	90%	83.4°
2032-01-31 Sat	89	—	unknown	19:15–00:10 (good, 4.92 h)	42.9° 21:15	10.8	83%	94.2°
2032-02-01 Sun	89	—	unknown	19:15–00:15 (good, 5.0 h)	42.9° 21:10	10.77	76%	105.2°
2032-02-02 Mon	89	—	unknown	19:15–00:20 (good, 5.08 h)	42.9° 21:10	10.74	66%	116.3°
2032-02-03 Tue	89	—	unknown	19:15–00:25 (good, 5.17 h)	42.9° 21:05	10.71	57%	127.2°
2032-02-04 Wed	89	—	unknown	19:15–00:20 (good, 5.08 h)	42.9° 21:00	10.67	46%	137.8°
2032-02-05 Thu	89	—	unknown	19:20–00:15 (good, 4.92 h)	42.9° 20:55	10.64	36%	147.2°
2032-02-06 Fri	89	—	unknown	19:20–00:10 (good, 4.83 h)	42.9° 20:50	10.6	25%	153.6°
2032-02-07 Sat	89	—	unknown	19:20–00:05 (good, 4.75 h)	42.9° 20:50	10.57	16%	153.7°
2032-02-08 Sun	89	—	unknown	19:20–00:05 (good, 4.75 h)	42.9° 20:45	10.53	8%	147.0°
2032-02-09 Mon	89	—	unknown	19:25–00:00 (good, 4.58 h)	42.9° 20:40	10.49	3%	136.3°
2032-02-10 Tue	89	—	unknown	19:25–23:55 (good, 4.5 h)	42.9° 20:35	10.46	0%	123.7°
2032-02-11 Wed	89	—	unknown	19:25–23:50 (good, 4.42 h)	42.9° 20:30	10.42	1%	110.3°
2032-02-12 Thu	89	—	unknown	19:25–23:50 (good, 4.42 h)	42.9° 20:30	10.38	4%	96.8°
2032-02-13 Fri	88	—	unknown	19:25–23:45 (good, 4.33 h)	42.9° 20:25	10.34	10%	83.5°
2032-02-14 Sat	83	—	unknown	19:30–23:40 (good, 4.17 h)	42.9° 20:20	10.3	18%	70.7°
2032-02-15 Sun	70	—	unknown	19:30–23:35 (good, 4.08 h)	42.9° 20:15	10.26	28%	58.5°
2032-02-16 Mon	56	—	unknown	19:30–23:15 (good, 3.75 h)	42.9° 20:15	10.22	38%	47.3°
2032-02-17 Tue	42	—	unknown	20:10–22:45 (good, 2.58 h)	42.9° 20:10	10.18	48%	37.4°
2032-02-18 Wed	29	—	unknown	19:35–23:50 (marginal, 4.25 h)	42.9° 20:05	10.14	58%	29.6°
2032-02-19 Thu	20	—	unknown	19:35–23:30 (marginal, 3.92 h)	42.9° 20:00	10.1	67%	25.6°
2032-02-20 Fri	14	—	unknown	19:35–23:10 (marginal, 3.58 h)	42.9° 19:55	10.06	76%	26.6°
2032-02-21 Sat	12	—	unknown	19:35–22:45 (marginal, 3.17 h)	42.9° 19:55	10.02	84%	32.1°
2032-02-22 Sun	13	—	unknown	19:35–22:35 (marginal, 3.0 h)	42.9° 19:50	9.98	90%	40.1°
2032-02-23 Mon	16	—	unknown	19:40–22:45 (marginal, 3.08 h)	42.9° 19:45	9.93	95%	49.4°
2032-02-24 Tue	21	—	unknown	19:40–22:55 (marginal, 3.25 h)	42.9° 19:40	9.89	98%	59.5°
2032-02-25 Wed	28	—	unknown	19:40–23:05 (marginal, 3.42 h)	42.9° 19:35	9.85	100%	69.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-01-27&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.