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: 04-21 (70), 04-22 (70), 04-23 (70), 04-19 (69), 04-20 (69) — by astronomy; check the weather when the night is within four days.

2029-03-25astronomy score per night — click a bar for that night2029-04-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-03-25 Sun	45	—	unknown	04:00–05:40 (good, 1.67 h)	87.2° 10:05	8.45	77%	119.5°
2029-03-26 Mon	45	—	unknown	03:55–05:40 (good, 1.75 h)	87.2° 10:00	8.39	86%	124.2°
2029-03-27 Tue	41	—	unknown	03:55–05:40 (good, 1.75 h)	87.2° 09:55	8.34	93%	126.7°
2029-03-28 Wed	40	—	unknown	03:50–05:35 (good, 1.75 h)	87.2° 09:55	8.28	98%	126.4°
2029-03-29 Thu	40	—	unknown	03:50–05:35 (good, 1.75 h)	87.2° 09:50	8.23	100%	123.2°
2029-03-30 Fri	40	—	unknown	03:45–05:35 (good, 1.83 h)	87.2° 09:45	8.18	99%	117.6°
2029-03-31 Sat	37	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:40	8.12	95%	110.3°
2029-04-01 Sun	36	—	unknown	03:45–05:30 (good, 1.75 h)	87.2° 09:35	8.07	88%	102.1°
2029-04-02 Mon	34	—	unknown	03:40–05:25 (good, 1.75 h)	87.2° 09:35	8.01	80%	93.5°
2029-04-03 Tue	36	—	unknown	03:35–05:25 (good, 1.83 h)	87.2° 09:30	7.96	70%	85.1°
2029-04-04 Wed	38	—	unknown	03:30–05:25 (good, 1.92 h)	87.2° 09:25	7.9	59%	77.1°
2029-04-05 Thu	41	—	unknown	03:20–05:20 (good, 2.0 h)	87.2° 09:20	7.85	49%	69.9°
2029-04-06 Fri	46	—	unknown	03:05–05:20 (good, 2.25 h)	87.2° 09:20	7.79	39%	63.6°
2029-04-07 Sat	51	—	unknown	03:00–05:15 (good, 2.25 h)	87.2° 09:15	7.73	29%	58.6°
2029-04-08 Sun	55	—	unknown	02:55–05:15 (good, 2.33 h)	87.2° 09:10	7.68	21%	55.1°
2029-04-09 Mon	59	—	unknown	02:50–05:15 (good, 2.42 h)	87.2° 09:05	7.62	14%	53.3°
2029-04-10 Tue	60	—	unknown	02:45–05:10 (good, 2.42 h)	87.2° 09:00	7.56	8%	53.3°
2029-04-11 Wed	61	—	unknown	02:45–05:10 (good, 2.42 h)	87.2° 09:00	7.51	4%	55.2°
2029-04-12 Thu	62	—	unknown	02:40–05:05 (good, 2.42 h)	87.2° 08:55	7.45	1%	58.6°
2029-04-13 Fri	63	—	unknown	02:35–05:05 (good, 2.5 h)	87.2° 08:50	7.39	0%	63.4°
2029-04-14 Sat	65	—	unknown	02:30–05:05 (good, 2.58 h)	87.2° 08:45	7.33	1%	69.1°
2029-04-15 Sun	65	—	unknown	02:25–05:00 (good, 2.58 h)	87.2° 08:40	7.28	4%	75.6°
2029-04-16 Mon	66	—	unknown	02:25–05:00 (good, 2.58 h)	87.2° 08:40	7.22	8%	82.6°
2029-04-17 Tue	68	—	unknown	02:20–05:00 (good, 2.67 h)	87.2° 08:35	7.16	14%	89.9°
2029-04-18 Wed	68	—	unknown	02:15–04:55 (good, 2.67 h)	87.2° 08:30	7.1	22%	97.3°
2029-04-19 Thu	69	—	unknown	02:10–04:55 (good, 2.75 h)	87.2° 08:25	7.05	31%	104.6°
2029-04-20 Fri	69	—	unknown	02:10–04:50 (good, 2.67 h)	87.2° 08:25	6.99	40%	111.6°
2029-04-21 Sat	70	—	unknown	02:10–04:50 (good, 2.67 h)	87.2° 08:20	6.93	51%	117.8°
2029-04-22 Sun	70	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:15	6.87	62%	122.9°
2029-04-23 Mon	70	—	unknown	02:05–04:45 (good, 2.67 h)	87.2° 08:10	6.81	73%	126.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-03-25&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.