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), 03-15 (39), 03-14 (38), 03-13 (37), 03-12 (36) — by astronomy; check the weather when the night is within four days.

2037-02-15astronomy score per night — click a bar for that night2037-03-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-02-15 Sun	16	—	unknown	05:20–05:45 (good, 0.42 h)	87.2° 11:35	10.23	0%	60.0°
2037-02-16 Mon	18	—	unknown	05:15–05:45 (good, 0.5 h)	87.2° 11:30	10.19	3%	61.2°
2037-02-17 Tue	18	—	unknown	05:10–05:40 (good, 0.5 h)	87.2° 11:25	10.15	7%	63.6°
2037-02-18 Wed	19	—	unknown	05:05–05:40 (good, 0.58 h)	87.2° 11:20	10.11	12%	67.2°
2037-02-19 Thu	20	—	unknown	05:05–05:40 (good, 0.58 h)	87.2° 11:20	10.07	19%	71.8°
2037-02-20 Fri	21	—	unknown	05:00–05:40 (good, 0.67 h)	87.2° 11:15	10.03	27%	77.1°
2037-02-21 Sat	22	—	unknown	04:55–05:35 (good, 0.67 h)	87.2° 11:10	9.98	36%	83.0°
2037-02-22 Sun	22	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.94	46%	89.3°
2037-02-23 Mon	23	—	unknown	04:50–05:35 (good, 0.75 h)	87.2° 11:05	9.9	57%	95.8°
2037-02-24 Tue	23	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 11:00	9.86	68%	102.3°
2037-02-25 Wed	25	—	unknown	04:40–05:30 (good, 0.83 h)	87.2° 10:55	9.81	78%	108.4°
2037-02-26 Thu	24	—	unknown	04:45–05:30 (good, 0.75 h)	87.2° 10:50	9.77	86%	113.7°
2037-02-27 Fri	22	—	unknown	04:45–05:25 (good, 0.67 h)	87.2° 10:45	9.72	94%	117.7°
2037-02-28 Sat	22	—	unknown	04:40–05:25 (good, 0.75 h)	87.2° 10:45	9.68	98%	119.8°
2037-03-01 Sun	22	—	unknown	04:40–05:25 (good, 0.75 h)	87.2° 10:40	9.63	100%	119.6°
2037-03-02 Mon	22	—	unknown	04:35–05:25 (good, 0.83 h)	87.2° 10:35	9.59	99%	117.2°
2037-03-03 Tue	21	—	unknown	04:35–05:20 (good, 0.75 h)	87.2° 10:30	9.54	94%	112.9°
2037-03-04 Wed	21	—	unknown	04:35–05:20 (good, 0.75 h)	87.2° 10:25	9.49	88%	107.2°
2037-03-05 Thu	21	—	unknown	04:30–05:20 (good, 0.83 h)	87.2° 10:25	9.45	79%	100.8°
2037-03-06 Fri	21	—	unknown	04:25–05:15 (good, 0.83 h)	87.2° 10:20	9.4	69%	94.0°
2037-03-07 Sat	22	—	unknown	04:20–05:15 (good, 0.92 h)	87.2° 10:15	9.35	59%	87.4°
2037-03-08 Sun	24	—	unknown	04:15–05:15 (good, 1.0 h)	87.2° 10:10	9.3	49%	81.0°
2037-03-09 Mon	26	—	unknown	04:05–05:10 (good, 1.08 h)	87.2° 10:10	9.26	39%	75.2°
2037-03-10 Tue	29	—	unknown	03:55–05:10 (good, 1.25 h)	87.2° 10:05	9.21	29%	70.0°
2037-03-11 Wed	33	—	unknown	03:45–05:10 (good, 1.42 h)	87.2° 10:00	9.16	21%	65.8°
2037-03-12 Thu	36	—	unknown	03:40–05:05 (good, 1.42 h)	87.2° 09:55	9.11	14%	62.6°
2037-03-13 Fri	37	—	unknown	03:35–05:05 (good, 1.5 h)	87.2° 09:50	9.06	8%	60.6°
2037-03-14 Sat	38	—	unknown	03:35–05:05 (good, 1.5 h)	87.2° 09:50	9.01	4%	60.0°
2037-03-15 Sun	39	—	unknown	03:30–05:00 (good, 1.5 h)	87.2° 09:45	8.96	1%	60.7°
2037-03-16 Mon	40	—	unknown	03:25–05:00 (good, 1.58 h)	87.2° 09:40	8.91	0%	62.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-02-15&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.