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 3C 273: 11-10 (4), 11-08 (3), 11-09 (3), 11-03 (1), 11-04 (1) — by astronomy; check the weather when the night is within four days.

2043-10-12astronomy score per night — click a bar for that night2043-11-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-10-12 Mon	0	—	unknown	—	50.1° 12:30	9.68	66%	122.4°
2043-10-13 Tue	0	—	unknown	—	50.1° 12:25	9.73	75%	135.1°
2043-10-14 Wed	0	—	unknown	—	50.1° 12:20	9.77	84%	148.2°
2043-10-15 Thu	0	—	unknown	—	50.1° 12:15	9.82	91%	161.6°
2043-10-16 Fri	0	—	unknown	—	50.1° 12:15	9.86	96%	173.7°
2043-10-17 Sat	0	—	unknown	—	50.1° 12:10	9.9	100%	167.7°
2043-10-18 Sun	0	—	unknown	—	50.1° 12:05	9.94	100%	153.5°
2043-10-19 Mon	0	—	unknown	—	50.1° 12:00	9.99	97%	138.8°
2043-10-20 Tue	0	—	unknown	—	50.1° 11:55	10.03	91%	123.9°
2043-10-21 Wed	0	—	unknown	—	50.1° 11:50	10.07	84%	109.1°
2043-10-22 Thu	0	—	unknown	—	50.1° 11:45	10.11	74%	94.6°
2043-10-23 Fri	0	—	unknown	—	50.1° 11:40	10.15	63%	80.4°
2043-10-24 Sat	0	—	unknown	—	50.1° 10:40	10.19	52%	66.6°
2043-10-25 Sun	0	—	unknown	—	50.1° 10:35	10.23	41%	53.1°
2043-10-26 Mon	0	—	unknown	—	50.1° 10:30	10.27	31%	39.9°
2043-10-27 Tue	0	—	unknown	—	50.1° 10:25	10.31	22%	27.2°
2043-10-28 Wed	0	—	unknown	—	50.1° 10:20	10.35	14%	15.0°
2043-10-29 Thu	0	—	unknown	—	50.1° 10:20	10.39	8%	5.5°
2043-10-30 Fri	0	—	unknown	—	50.1° 10:15	10.42	3%	12.1°
2043-10-31 Sat	0	—	unknown	—	50.1° 10:10	10.46	1%	23.6°
2043-11-01 Sun	0	—	unknown	—	50.1° 10:05	10.5	0%	35.4°
2043-11-02 Mon	0	—	unknown	—	50.1° 10:00	10.53	1%	47.2°
2043-11-03 Tue	1	—	unknown	—	50.1° 10:00	10.57	4%	59.0°
2043-11-04 Wed	1	—	unknown	—	50.1° 09:55	10.6	8%	70.7°
2043-11-05 Thu	1	—	unknown	—	50.1° 09:50	10.64	14%	82.5°
2043-11-06 Fri	1	—	unknown	—	50.1° 09:45	10.67	22%	94.3°
2043-11-07 Sat	1	—	unknown	05:55–06:00 (marginal, 0.08 h)	50.1° 09:45	10.71	30%	106.2°
2043-11-08 Sun	3	—	unknown	05:50–06:00 (marginal, 0.17 h)	50.1° 09:40	10.74	39%	118.3°
2043-11-09 Mon	3	—	unknown	05:50–06:05 (marginal, 0.25 h)	50.1° 09:35	10.77	49%	130.6°
2043-11-10 Tue	4	—	unknown	05:15–05:30 (marginal, 0.25 h)	50.1° 09:30	10.8	59%	143.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-10-12&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.