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: 07-14 (100), 07-15 (100), 07-16 (100), 07-17 (100), 07-18 (100) — by astronomy; check the weather when the night is within four days.

2047-07-13astronomy score per night — click a bar for that night2047-08-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-07-13 Sat	98	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.91	60%	57.3°
2047-07-14 Sun	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:50	4.95	51%	61.7°
2047-07-15 Mon	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.0	41%	67.2°
2047-07-16 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.1° 02:45	5.04	32%	73.4°
2047-07-17 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.08	24%	80.2°
2047-07-18 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:35	5.13	16%	87.3°
2047-07-19 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.17	9%	94.7°
2047-07-20 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.22	4%	102.0°
2047-07-21 Sun	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:25	5.27	1%	109.1°
2047-07-22 Mon	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.32	0%	115.6°
2047-07-23 Tue	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:15	5.37	1%	121.1°
2047-07-24 Wed	100	—	unknown	22:50–04:15 (good, 5.42 h)	87.2° 02:10	5.42	5%	125.0°
2047-07-25 Thu	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.1° 02:05	5.47	10%	126.8°
2047-07-26 Fri	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.52	18%	126.1°
2047-07-27 Sat	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.2° 02:00	5.57	28%	123.0°
2047-07-28 Sun	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.63	39%	117.8°
2047-07-29 Mon	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.68	50%	111.1°
2047-07-30 Tue	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.1° 01:50	5.73	62%	103.3°
2047-07-31 Wed	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:45	5.79	72%	95.1°
2047-08-01 Thu	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.84	82%	86.6°
2047-08-02 Fri	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.9	90%	78.3°
2047-08-03 Sat	99	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	5.95	96%	70.6°
2047-08-04 Sun	66	—	unknown	01:55–04:30 (good, 2.58 h)	87.1° 01:30	6.01	99%	63.9°
2047-08-05 Mon	58	—	unknown	22:30–04:30 (marginal, 6.0 h)	87.2° 01:25	6.07	100%	58.5°
2047-08-06 Tue	56	—	unknown	22:25–04:35 (marginal, 6.17 h)	87.2° 01:20	6.12	99%	54.8°
2047-08-07 Wed	58	—	unknown	22:25–23:00 (good, 0.58 h)	87.2° 01:15	6.18	95%	53.3°
2047-08-08 Thu	67	—	unknown	22:20–23:50 (good, 1.5 h)	87.1° 01:10	6.24	90%	53.8°
2047-08-09 Fri	72	—	unknown	22:20–01:10 (good, 2.83 h)	87.2° 01:10	6.29	83%	56.2°
2047-08-10 Sat	100	—	unknown	22:20–03:40 (good, 5.33 h)	87.2° 01:05	6.35	75%	60.2°
2047-08-11 Sun	100	—	unknown	22:15–04:40 (good, 6.42 h)	87.2° 01:00	6.41	67%	65.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-07-13&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.