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: 04-09 (59), 04-07 (58), 04-08 (58), 04-06 (56), 04-05 (54) — by astronomy; check the weather when the night is within four days.

2043-03-11astronomy score per night — click a bar for that night2043-04-09

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2043-03-20 Fri	39	—	unknown	03:25–04:50 (good, 1.42 h)	87.2° 09:25	8.73	79%	112.3°
2043-03-21 Sat	36	—	unknown	03:20–04:50 (good, 1.5 h)	87.2° 09:25	8.68	87%	116.3°
2043-03-22 Sun	36	—	unknown	03:15–04:50 (good, 1.58 h)	87.2° 09:20	8.62	93%	119.0°
2043-03-23 Mon	36	—	unknown	03:15–04:45 (good, 1.5 h)	87.2° 09:15	8.57	97%	120.2°
2043-03-24 Tue	36	—	unknown	03:10–04:45 (good, 1.58 h)	87.2° 09:10	8.52	100%	119.8°
2043-03-25 Wed	36	—	unknown	03:05–04:45 (good, 1.67 h)	87.2° 09:05	8.47	100%	117.9°
2043-03-26 Thu	35	—	unknown	03:05–04:40 (good, 1.58 h)	87.2° 09:05	8.41	98%	114.8°
2043-03-27 Fri	35	—	unknown	03:05–04:40 (good, 1.58 h)	87.2° 09:00	8.36	95%	110.6°
2043-03-28 Sat	33	—	unknown	04:00–05:35 (good, 1.58 h)	87.2° 09:55	8.31	90%	105.7°
2043-03-29 Sun	34	—	unknown	03:55–05:35 (good, 1.67 h)	87.2° 09:50	8.25	84%	100.3°
2043-03-30 Mon	35	—	unknown	03:55–05:35 (good, 1.67 h)	87.2° 09:45	8.2	76%	94.5°
2043-03-31 Tue	35	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:45	8.14	68%	88.5°
2043-04-01 Wed	38	—	unknown	03:40–05:30 (good, 1.83 h)	87.2° 09:40	8.09	58%	82.5°
2043-04-02 Thu	42	—	unknown	03:20–05:30 (good, 2.17 h)	87.2° 09:35	8.03	49%	76.6°
2043-04-03 Fri	48	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.98	38%	71.1°
2043-04-04 Sat	52	—	unknown	03:10–05:25 (good, 2.25 h)	87.2° 09:30	7.92	29%	66.3°
2043-04-05 Sun	54	—	unknown	03:10–05:20 (good, 2.17 h)	87.2° 09:25	7.87	19%	62.5°
2043-04-06 Mon	56	—	unknown	03:05–05:20 (good, 2.25 h)	87.2° 09:20	7.81	11%	60.2°
2043-04-07 Tue	58	—	unknown	03:00–05:20 (good, 2.33 h)	87.2° 09:15	7.76	5%	59.9°
2043-04-08 Wed	58	—	unknown	02:55–05:15 (good, 2.33 h)	87.2° 09:10	7.7	1%	61.7°
2043-04-09 Thu	59	—	unknown	02:55–05:15 (good, 2.33 h)	87.2° 09:10	7.64	0%	65.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-03-11&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.