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 North America Nebula: 04-03 (55), 04-05 (55), 04-06 (55), 04-01 (54), 04-02 (54) — by astronomy; check the weather when the night is within four days.

2044-03-12astronomy score per night — click a bar for that night2044-04-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-03-12 Sat	29	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 09:55	9.09	99%	121.7°
2044-03-13 Sun	30	—	unknown	03:50–05:05 (good, 1.25 h)	87.2° 09:50	9.04	100%	121.6°
2044-03-14 Mon	30	—	unknown	03:45–05:00 (good, 1.25 h)	87.2° 09:45	8.99	99%	119.6°
2044-03-15 Tue	30	—	unknown	03:45–05:00 (good, 1.25 h)	87.2° 09:45	8.94	95%	116.0°
2044-03-16 Wed	29	—	unknown	03:40–05:00 (good, 1.33 h)	87.2° 09:40	8.89	90%	111.3°
2044-03-17 Thu	29	—	unknown	03:40–04:55 (good, 1.25 h)	87.2° 09:35	8.84	83%	105.8°
2044-03-18 Fri	30	—	unknown	03:35–04:55 (good, 1.33 h)	87.2° 09:30	8.79	75%	99.9°
2044-03-19 Sat	31	—	unknown	03:30–04:55 (good, 1.42 h)	87.2° 09:25	8.74	66%	93.7°
2044-03-20 Sun	31	—	unknown	03:25–04:50 (good, 1.42 h)	87.2° 09:25	8.69	57%	87.4°
2044-03-21 Mon	34	—	unknown	03:15–04:50 (good, 1.58 h)	87.2° 09:20	8.64	48%	81.3°
2044-03-22 Tue	37	—	unknown	03:00–04:45 (good, 1.75 h)	87.2° 09:15	8.58	38%	75.4°
2044-03-23 Wed	42	—	unknown	02:55–04:45 (good, 1.83 h)	87.2° 09:10	8.53	29%	69.9°
2044-03-24 Thu	45	—	unknown	02:55–04:45 (good, 1.83 h)	87.2° 09:10	8.48	21%	65.1°
2044-03-25 Fri	46	—	unknown	02:50–04:40 (good, 1.83 h)	87.2° 09:05	8.43	13%	61.3°
2044-03-26 Sat	48	—	unknown	02:45–05:40 (good, 1.92 h)	87.2° 10:00	8.37	7%	58.8°
2044-03-27 Sun	49	—	unknown	03:40–05:40 (good, 2.0 h)	87.2° 09:55	8.32	3%	58.1°
2044-03-28 Mon	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.2° 09:50	8.27	0%	59.3°
2044-03-29 Tue	50	—	unknown	03:35–05:35 (good, 2.0 h)	87.2° 09:50	8.21	0%	62.5°
2044-03-30 Wed	50	—	unknown	03:30–05:30 (good, 2.0 h)	87.2° 09:45	8.16	3%	67.4°
2044-03-31 Thu	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.1	8%	73.6°
2044-04-01 Fri	54	—	unknown	03:20–05:30 (good, 2.17 h)	87.2° 09:35	8.05	16%	80.7°
2044-04-02 Sat	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.99	25%	88.2°
2044-04-03 Sun	55	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.94	36%	95.7°
2044-04-04 Mon	54	—	unknown	03:15–05:20 (good, 2.08 h)	87.2° 09:25	7.88	47%	102.9°
2044-04-05 Tue	55	—	unknown	03:15–05:20 (good, 2.08 h)	87.2° 09:20	7.83	59%	109.5°
2044-04-06 Wed	55	—	unknown	03:10–05:20 (good, 2.17 h)	87.2° 09:15	7.77	70%	115.0°
2044-04-07 Thu	54	—	unknown	03:05–05:15 (good, 2.17 h)	87.2° 09:15	7.71	79%	119.0°
2044-04-08 Fri	50	—	unknown	03:05–05:15 (good, 2.17 h)	87.2° 09:10	7.66	87%	121.4°
2044-04-09 Sat	50	—	unknown	03:00–05:15 (good, 2.25 h)	87.2° 09:05	7.6	94%	121.8°
2044-04-10 Sun	49	—	unknown	03:00–05:10 (good, 2.17 h)	87.2° 09:00	7.54	98%	120.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-03-12&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.