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: 04-13 (63), 04-11 (62), 04-12 (62), 04-09 (60), 04-10 (60) — by astronomy; check the weather when the night is within four days.

2048-03-15astronomy score per night — click a bar for that night2048-04-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2048-03-15 Sun	39	—	unknown	03:30–05:00 (good, 1.5 h)	87.2° 09:45	8.94	2%	58.3°
2048-03-16 Mon	40	—	unknown	03:25–05:00 (good, 1.58 h)	87.2° 09:40	8.89	6%	63.3°
2048-03-17 Tue	40	—	unknown	03:20–04:55 (good, 1.58 h)	87.2° 09:35	8.84	11%	69.3°
2048-03-18 Wed	42	—	unknown	03:15–04:55 (good, 1.67 h)	87.2° 09:30	8.79	18%	75.9°
2048-03-19 Thu	43	—	unknown	03:10–04:55 (good, 1.75 h)	87.1° 09:30	8.74	25%	82.9°
2048-03-20 Fri	42	—	unknown	03:10–04:50 (good, 1.67 h)	87.2° 09:25	8.69	34%	90.0°
2048-03-21 Sat	44	—	unknown	03:05–04:50 (good, 1.75 h)	87.2° 09:20	8.64	43%	97.1°
2048-03-22 Sun	44	—	unknown	03:00–04:45 (good, 1.75 h)	87.2° 09:15	8.58	52%	104.1°
2048-03-23 Mon	45	—	unknown	02:55–04:45 (good, 1.83 h)	87.2° 09:10	8.53	62%	110.8°
2048-03-24 Tue	46	—	unknown	03:00–04:45 (good, 1.75 h)	87.1° 09:10	8.48	71%	116.8°
2048-03-25 Wed	45	—	unknown	02:55–04:40 (good, 1.75 h)	87.2° 09:05	8.42	80%	121.9°
2048-03-26 Thu	45	—	unknown	02:55–04:40 (good, 1.75 h)	87.2° 09:00	8.37	88%	125.5°
2048-03-27 Fri	41	—	unknown	02:50–04:40 (good, 1.83 h)	87.2° 08:55	8.32	94%	127.1°
2048-03-28 Sat	41	—	unknown	02:50–05:35 (good, 1.75 h)	87.1° 09:50	8.26	98%	126.3°
2048-03-29 Sun	41	—	unknown	03:45–05:35 (good, 1.83 h)	87.2° 09:50	8.21	100%	123.0°
2048-03-30 Mon	39	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:45	8.15	99%	117.4°
2048-03-31 Tue	38	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:40	8.1	95%	110.3°
2048-04-01 Wed	36	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:35	8.05	89%	102.1°
2048-04-02 Thu	35	—	unknown	03:40–05:25 (good, 1.75 h)	87.1° 09:30	7.99	80%	93.4°
2048-04-03 Fri	35	—	unknown	03:35–05:25 (good, 1.83 h)	87.2° 09:30	7.93	70%	84.6°
2048-04-04 Sat	36	—	unknown	03:30–05:20 (good, 1.83 h)	87.2° 09:25	7.88	59%	76.2°
2048-04-05 Sun	41	—	unknown	03:20–05:20 (good, 2.0 h)	87.2° 09:20	7.82	48%	68.6°
2048-04-06 Mon	47	—	unknown	03:00–05:20 (good, 2.33 h)	87.2° 09:15	7.77	37%	62.0°
2048-04-07 Tue	52	—	unknown	02:55–05:15 (good, 2.33 h)	87.1° 09:15	7.71	27%	56.9°
2048-04-08 Wed	56	—	unknown	02:55–05:15 (good, 2.33 h)	87.2° 09:10	7.65	18%	53.8°
2048-04-09 Thu	60	—	unknown	02:50–05:15 (good, 2.42 h)	87.2° 09:05	7.6	11%	52.8°
2048-04-10 Fri	60	—	unknown	02:45–05:10 (good, 2.42 h)	87.2° 09:00	7.54	5%	53.9°
2048-04-11 Sat	62	—	unknown	02:40–05:10 (good, 2.5 h)	87.1° 08:55	7.48	2%	57.1°
2048-04-12 Sun	62	—	unknown	02:40–05:05 (good, 2.42 h)	87.2° 08:55	7.43	0%	61.7°
2048-04-13 Mon	63	—	unknown	02:35–05:05 (good, 2.5 h)	87.2° 08:50	7.37	1%	67.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2048-03-15&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.