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: 02-16 (87), 02-15 (86), 02-17 (86), 02-18 (84), 02-14 (83) — by astronomy; check the weather when the night is within four days.

2036-02-08astronomy score per night — click a bar for that night2036-03-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-02-08 Fri	13	—	unknown	19:20–20:30 (marginal, 1.17 h)	42.9° 20:45	10.53	87%	28.5°
2036-02-09 Sat	14	—	unknown	19:25–21:30 (marginal, 2.08 h)	42.9° 20:40	10.49	94%	38.4°
2036-02-10 Sun	21	—	unknown	19:25–23:25 (marginal, 4.0 h)	42.9° 20:35	10.46	98%	50.7°
2036-02-11 Mon	32	—	unknown	19:25–23:45 (marginal, 4.33 h)	42.9° 20:30	10.42	100%	63.9°
2036-02-12 Tue	46	—	unknown	19:25–21:00 (good, 1.58 h)	42.9° 20:30	10.38	98%	77.4°
2036-02-13 Wed	75	—	unknown	19:25–22:55 (good, 3.5 h)	42.9° 20:25	10.34	94%	90.7°
2036-02-14 Thu	83	—	unknown	19:30–23:20 (good, 3.83 h)	42.9° 20:20	10.3	88%	103.7°
2036-02-15 Fri	86	—	unknown	19:30–23:25 (good, 3.92 h)	42.9° 20:15	10.26	80%	116.1°
2036-02-16 Sat	87	—	unknown	19:30–23:25 (good, 3.92 h)	42.9° 20:15	10.22	70%	127.8°
2036-02-17 Sun	86	—	unknown	19:30–23:30 (good, 4.0 h)	42.9° 20:10	10.18	60%	138.5°
2036-02-18 Mon	84	—	unknown	19:35–23:25 (good, 3.83 h)	42.9° 20:05	10.14	50%	147.6°
2036-02-19 Tue	82	—	unknown	19:35–23:20 (good, 3.75 h)	42.9° 20:00	10.1	41%	154.0°
2036-02-20 Wed	80	—	unknown	19:35–23:15 (good, 3.67 h)	42.9° 19:55	10.06	32%	156.0°
2036-02-21 Thu	80	—	unknown	19:35–23:10 (good, 3.58 h)	42.9° 19:55	10.02	23%	152.7°
2036-02-22 Fri	78	—	unknown	19:35–23:10 (good, 3.58 h)	42.9° 19:50	9.97	16%	145.7°
2036-02-23 Sat	76	—	unknown	19:40–23:05 (good, 3.42 h)	42.9° 19:45	9.93	10%	136.8°
2036-02-24 Sun	74	—	unknown	19:40–23:00 (good, 3.33 h)	42.9° 19:40	9.89	5%	126.9°
2036-02-25 Mon	73	—	unknown	19:40–22:55 (good, 3.25 h)	42.9° 19:35	9.84	2%	116.3°
2036-02-26 Tue	71	—	unknown	19:40–22:55 (good, 3.25 h)	42.9° 19:35	9.8	0%	105.4°
2036-02-27 Wed	69	—	unknown	19:45–22:50 (good, 3.08 h)	42.9° 19:30	9.76	0%	94.2°
2036-02-28 Thu	67	—	unknown	19:45–22:45 (good, 3.0 h)	42.9° 19:25	9.71	3%	82.8°
2036-02-29 Fri	64	—	unknown	19:45–22:40 (good, 2.92 h)	42.9° 19:20	9.67	7%	71.3°
2036-03-01 Sat	59	—	unknown	19:45–22:35 (good, 2.83 h)	42.9° 19:20	9.62	14%	59.8°
2036-03-02 Sun	51	—	unknown	19:50–22:25 (good, 2.58 h)	42.9° 19:15	9.57	22%	48.5°
2036-03-03 Mon	41	—	unknown	19:50–22:10 (good, 2.33 h)	42.9° 19:10	9.53	31%	37.9°
2036-03-04 Tue	30	—	unknown	19:50–21:50 (good, 2.0 h)	42.9° 19:05	9.48	42%	28.9°
2036-03-05 Wed	22	—	unknown	19:50–22:45 (marginal, 2.92 h)	42.9° 19:00	9.44	53%	24.1°
2036-03-06 Thu	15	—	unknown	19:55–22:30 (marginal, 2.58 h)	42.9° 19:00	9.39	64%	26.3°
2036-03-07 Fri	11	—	unknown	19:55–22:05 (marginal, 2.17 h)	42.9° 18:55	9.34	75%	34.4°
2036-03-08 Sat	11	—	unknown	19:55–22:00 (marginal, 2.08 h)	42.9° 18:50	9.29	84%	45.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-02-08&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.