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: 07-25 (100), 07-26 (100), 07-27 (100), 07-28 (100), 07-29 (100) — by astronomy; check the weather when the night is within four days.

2046-07-25astronomy score per night — click a bar for that night2046-08-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-07-25 Wed	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.48	52%	65.7°
2046-07-26 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 02:00	5.53	42%	71.7°
2046-07-27 Fri	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.2° 02:00	5.59	33%	78.4°
2046-07-28 Sat	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.64	23%	85.6°
2046-07-29 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.69	15%	93.3°
2046-07-30 Mon	100	—	unknown	22:40–04:25 (good, 5.75 h)	87.2° 01:45	5.75	8%	101.1°
2046-07-31 Tue	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.1° 01:45	5.8	3%	108.6°
2046-08-01 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.86	0%	115.5°
2046-08-02 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.91	0%	121.1°
2046-08-03 Fri	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	5.97	3%	124.7°
2046-08-04 Sat	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:25	6.02	9%	125.7°
2046-08-05 Sun	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.2° 01:25	6.08	17%	124.1°
2046-08-06 Mon	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.2° 01:20	6.14	27%	120.0°
2046-08-07 Tue	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.2° 01:15	6.19	37%	114.2°
2046-08-08 Wed	100	—	unknown	22:20–04:35 (good, 6.25 h)	87.2° 01:10	6.25	49%	107.3°
2046-08-09 Thu	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.2° 01:05	6.31	60%	99.8°
2046-08-10 Fri	100	—	unknown	22:20–04:40 (good, 6.33 h)	87.2° 01:05	6.36	70%	92.0°
2046-08-11 Sat	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.2° 01:00	6.42	79%	84.4°
2046-08-12 Sun	100	—	unknown	22:15–04:45 (good, 6.5 h)	87.2° 00:55	6.48	87%	77.0°
2046-08-13 Mon	98	—	unknown	22:15–04:45 (good, 6.5 h)	87.2° 00:50	6.54	93%	70.3°
2046-08-14 Tue	67	—	unknown	22:10–04:45 (good, 6.58 h)	87.1° 00:50	6.59	97%	64.4°
2046-08-15 Wed	60	—	unknown	22:10–22:15 (good, 0.08 h)	87.2° 00:45	6.65	100%	59.6°
2046-08-16 Thu	60	—	unknown	21:30–04:50 (marginal, 7.33 h)	87.2° 00:40	6.71	100%	56.2°
2046-08-17 Fri	60	—	unknown	22:05–22:15 (good, 0.17 h)	87.2° 00:35	6.77	98%	54.5°
2046-08-18 Sat	63	—	unknown	22:05–22:50 (good, 0.75 h)	87.2° 00:30	6.82	95%	54.5°
2046-08-19 Sun	68	—	unknown	22:00–23:45 (good, 1.75 h)	87.2° 00:30	6.88	90%	56.3°
2046-08-20 Mon	73	—	unknown	22:00–01:10 (good, 3.17 h)	87.2° 00:25	6.94	84%	59.6°
2046-08-21 Tue	100	—	unknown	21:55–03:25 (good, 5.5 h)	87.2° 00:20	7.0	76%	64.2°
2046-08-22 Wed	100	—	unknown	21:55–04:35 (good, 6.67 h)	87.2° 00:15	7.05	68%	69.8°
2046-08-23 Thu	100	—	unknown	21:55–05:00 (good, 7.08 h)	87.2° 00:10	7.11	58%	76.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-07-25&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.