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: 01-13 (89), 01-14 (89), 01-15 (89), 01-16 (89), 01-31 (89) — by astronomy; check the weather when the night is within four days.

2032-01-13astronomy score per night — click a bar for that night2032-02-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-01-13 Tue	89	—	unknown	19:10–01:45 (good, 6.58 h)	42.9° 22:25	11.28	2%	130.5°
2032-01-14 Wed	89	—	unknown	19:10–01:40 (good, 6.5 h)	42.9° 22:20	11.26	7%	117.5°
2032-01-15 Thu	89	—	unknown	19:05–01:40 (good, 6.58 h)	42.9° 22:20	11.23	14%	104.4°
2032-01-16 Fri	89	—	unknown	19:05–01:35 (good, 6.5 h)	42.9° 22:15	11.21	23%	91.3°
2032-01-17 Sat	87	—	unknown	19:10–01:30 (good, 6.33 h)	42.9° 22:10	11.19	33%	78.6°
2032-01-18 Sun	83	—	unknown	19:20–01:25 (good, 6.08 h)	42.9° 22:05	11.17	44%	66.5°
2032-01-19 Mon	66	—	unknown	20:35–01:00 (good, 4.42 h)	42.9° 22:05	11.14	55%	55.0°
2032-01-20 Tue	51	—	unknown	19:00–01:50 (marginal, 6.83 h)	42.9° 22:00	11.12	65%	44.4°
2032-01-21 Wed	34	—	unknown	19:00–01:35 (marginal, 6.58 h)	42.9° 21:55	11.09	74%	35.2°
2032-01-22 Thu	21	—	unknown	19:05–01:10 (marginal, 6.08 h)	42.9° 21:50	11.07	82%	28.4°
2032-01-23 Fri	15	—	unknown	00:15–00:35 (marginal, 0.33 h)	42.9° 21:45	11.04	89%	25.6°
2032-01-24 Sat	13	—	unknown	—	42.9° 21:45	11.01	94%	27.8°
2032-01-25 Sun	15	—	unknown	19:05–20:30 (marginal, 1.42 h)	42.9° 21:40	10.99	98%	34.0°
2032-01-26 Mon	22	—	unknown	19:05–22:40 (marginal, 3.58 h)	42.9° 21:35	10.96	100%	42.4°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-01-13&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.