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: 06-21 (100), 06-22 (100), 06-23 (100), 06-24 (100), 06-25 (100) — by astronomy; check the weather when the night is within four days.

2034-06-21astronomy score per night — click a bar for that night2034-07-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-06-21 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	34%	123.9°
2034-06-22 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	43%	121.7°
2034-06-23 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	53%	118.0°
2034-06-24 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.44	63%	113.2°
2034-06-25 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.45	72%	107.6°
2034-06-26 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.46	80%	101.4°
2034-06-27 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.47	87%	94.9°
2034-06-28 Wed	80	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:50	4.48	92%	88.1°
2034-06-29 Thu	72	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:50	4.5	97%	81.4°
2034-06-30 Fri	62	—	unknown	23:55–03:45 (good, 3.83 h)	87.2° 03:45	4.52	99%	74.9°
2034-07-01 Sat	54	—	unknown	00:35–03:45 (good, 3.17 h)	87.2° 03:40	4.54	100%	68.8°
2034-07-02 Sun	49	—	unknown	23:10–03:45 (marginal, 4.58 h)	87.2° 03:35	4.56	98%	63.4°
2034-07-03 Mon	50	—	unknown	00:25–01:00 (good, 0.58 h)	87.2° 03:35	4.59	95%	59.2°
2034-07-04 Tue	55	—	unknown	23:10–01:50 (good, 2.67 h)	87.2° 03:30	4.61	89%	56.5°
2034-07-05 Wed	86	—	unknown	23:10–03:20 (good, 4.17 h)	87.2° 03:25	4.64	82%	55.7°
2034-07-06 Thu	95	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.67	73%	57.1°
2034-07-07 Fri	99	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:15	4.7	63%	60.4°
2034-07-08 Sat	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.73	52%	65.5°
2034-07-09 Sun	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.77	40%	72.0°
2034-07-10 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.8	29%	79.5°
2034-07-11 Tue	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.84	19%	87.5°
2034-07-12 Wed	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 02:55	4.88	11%	95.7°
2034-07-13 Thu	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.92	5%	103.6°
2034-07-14 Fri	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:50	4.96	1%	110.8°
2034-07-15 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.0	0%	116.9°
2034-07-16 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.04	2%	121.3°
2034-07-17 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:40	5.09	6%	123.8°
2034-07-18 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:35	5.13	12%	124.1°
2034-07-19 Wed	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.18	19%	122.5°
2034-07-20 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.23	28%	119.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-06-21&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.