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: 03-16 (40), 03-17 (40), 03-18 (40), 03-19 (40), 03-14 (38) — by astronomy; check the weather when the night is within four days.

2043-02-18astronomy score per night — click a bar for that night2043-03-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-02-18 Wed	18	—	unknown	05:10–05:40 (good, 0.5 h)	87.2° 11:25	10.13	74%	96.0°
2043-02-19 Thu	18	—	unknown	05:20–05:40 (good, 0.33 h)	87.2° 11:20	10.09	83%	102.6°
2043-02-20 Fri	16	—	unknown	05:15–05:40 (good, 0.42 h)	87.2° 11:15	10.05	90%	108.5°
2043-02-21 Sat	16	—	unknown	05:10–05:35 (good, 0.42 h)	87.2° 11:15	10.0	96%	113.5°
2043-02-22 Sun	17	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:10	9.96	99%	117.3°
2043-02-23 Mon	18	—	unknown	05:05–05:35 (good, 0.5 h)	87.2° 11:05	9.92	100%	119.6°
2043-02-24 Tue	19	—	unknown	05:00–05:35 (good, 0.58 h)	87.2° 11:00	9.88	99%	120.2°
2043-02-25 Wed	19	—	unknown	04:55–05:30 (good, 0.58 h)	87.2° 10:55	9.83	96%	119.4°
2043-02-26 Thu	19	—	unknown	04:55–05:30 (good, 0.58 h)	87.2° 10:55	9.79	91%	117.1°
2043-02-27 Fri	19	—	unknown	04:50–05:30 (good, 0.67 h)	87.2° 10:50	9.74	85%	113.6°
2043-02-28 Sat	20	—	unknown	04:45–05:25 (good, 0.67 h)	87.2° 10:45	9.7	78%	109.1°
2043-03-01 Sun	20	—	unknown	04:40–05:25 (good, 0.75 h)	87.2° 10:40	9.65	70%	104.0°
2043-03-02 Mon	22	—	unknown	04:35–05:25 (good, 0.83 h)	87.2° 10:35	9.61	60%	98.5°
2043-03-03 Tue	22	—	unknown	04:30–05:20 (good, 0.83 h)	87.2° 10:35	9.56	51%	92.5°
2043-03-04 Wed	24	—	unknown	04:25–05:20 (good, 0.92 h)	87.2° 10:30	9.51	41%	86.5°
2043-03-05 Thu	26	—	unknown	04:20–05:20 (good, 1.0 h)	87.2° 10:25	9.47	32%	80.4°
2043-03-06 Fri	30	—	unknown	04:05–05:15 (good, 1.17 h)	87.2° 10:20	9.42	23%	74.5°
2043-03-07 Sat	32	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:20	9.37	15%	69.1°
2043-03-08 Sun	33	—	unknown	04:00–05:15 (good, 1.25 h)	87.2° 10:15	9.33	8%	64.5°
2043-03-09 Mon	33	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:10	9.28	3%	61.3°
2043-03-10 Tue	35	—	unknown	03:50–05:10 (good, 1.33 h)	87.2° 10:05	9.23	0%	59.8°
2043-03-11 Wed	36	—	unknown	03:45–05:10 (good, 1.42 h)	87.2° 10:00	9.18	0%	60.4°
2043-03-12 Thu	35	—	unknown	03:45–05:05 (good, 1.33 h)	87.2° 10:00	9.13	3%	63.1°
2043-03-13 Fri	37	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.08	9%	67.7°
2043-03-14 Sat	38	—	unknown	03:35–05:05 (good, 1.5 h)	87.2° 09:50	9.03	17%	73.6°
2043-03-15 Sun	38	—	unknown	03:30–05:00 (good, 1.5 h)	87.2° 09:45	8.98	27%	80.2°
2043-03-16 Mon	40	—	unknown	03:25–05:00 (good, 1.58 h)	87.2° 09:40	8.93	38%	87.3°
2043-03-17 Tue	40	—	unknown	03:25–05:00 (good, 1.58 h)	87.2° 09:40	8.88	49%	94.3°
2043-03-18 Wed	40	—	unknown	03:20–04:55 (good, 1.58 h)	87.2° 09:35	8.83	60%	101.0°
2043-03-19 Thu	40	—	unknown	03:25–04:55 (good, 1.5 h)	87.2° 09:30	8.78	70%	107.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-02-18&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.