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: 03-07 (33), 03-06 (32), 03-08 (32), 03-09 (32), 03-04 (31) — by astronomy; check the weather when the night is within four days.

2044-02-18astronomy score per night — click a bar for that night2044-03-18

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-02-18 Thu	14	—	unknown	05:25–05:40 (good, 0.25 h)	87.2° 11:25	10.14	68%	109.3°
2044-02-19 Fri	15	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:20	10.1	59%	103.7°
2044-02-20 Sat	17	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:20	10.06	49%	97.7°
2044-02-21 Sun	17	—	unknown	05:10–05:35 (good, 0.42 h)	87.2° 11:15	10.01	40%	91.5°
2044-02-22 Mon	19	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:10	9.97	31%	85.3°
2044-02-23 Tue	21	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.93	22%	79.2°
2044-02-24 Wed	23	—	unknown	04:45–05:35 (good, 0.83 h)	87.2° 11:00	9.89	15%	73.3°
2044-02-25 Thu	24	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 11:00	9.84	9%	68.0°
2044-02-26 Fri	24	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.8	4%	63.5°
2044-02-27 Sat	26	—	unknown	04:35–05:30 (good, 0.92 h)	87.2° 10:50	9.75	1%	60.2°
2044-02-28 Sun	26	—	unknown	04:30–05:25 (good, 0.92 h)	87.2° 10:45	9.71	0%	58.3°
2044-02-29 Mon	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.66	1%	58.3°
2044-03-01 Tue	28	—	unknown	04:25–05:25 (good, 1.0 h)	87.2° 10:40	9.62	5%	60.3°
2044-03-02 Wed	28	—	unknown	04:20–05:20 (good, 1.0 h)	87.2° 10:35	9.57	11%	64.0°
2044-03-03 Thu	30	—	unknown	04:15–05:20 (good, 1.08 h)	87.2° 10:30	9.53	19%	69.2°
2044-03-04 Fri	31	—	unknown	04:10–05:20 (good, 1.17 h)	87.2° 10:25	9.48	28%	75.5°
2044-03-05 Sat	31	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:25	9.43	39%	82.5°
2044-03-06 Sun	32	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.38	51%	89.9°
2044-03-07 Mon	33	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.34	62%	97.4°
2044-03-08 Tue	32	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:10	9.29	73%	104.5°
2044-03-09 Wed	32	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:05	9.24	82%	110.9°
2044-03-10 Thu	29	—	unknown	04:00–05:10 (good, 1.17 h)	87.2° 10:05	9.19	90%	116.1°
2044-03-11 Fri	29	—	unknown	03:55–05:05 (good, 1.17 h)	87.2° 10:00	9.14	96%	119.9°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-02-18&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.