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: 06-15 (29), 06-16 (29), 06-17 (27), 06-18 (26), 06-19 (24) — by astronomy; check the weather when the night is within four days.

2047-06-15astronomy score per night — click a bar for that night2047-07-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-06-15 Sat	29	—	unknown	23:10–00:10 (good, 1.0 h)	50.1° 20:15	4.45	44%	169.2°
2047-06-16 Sun	29	—	unknown	23:10–00:05 (good, 0.92 h)	50.1° 20:15	4.44	35%	167.4°
2047-06-17 Mon	27	—	unknown	23:10–00:00 (good, 0.83 h)	50.1° 20:10	4.44	26%	158.1°
2047-06-18 Tue	26	—	unknown	23:10–23:55 (good, 0.75 h)	50.1° 20:05	4.43	18%	147.2°
2047-06-19 Wed	24	—	unknown	23:10–23:55 (good, 0.75 h)	50.1° 20:00	4.42	12%	135.8°
2047-06-20 Thu	22	—	unknown	23:15–23:50 (good, 0.58 h)	50.1° 19:55	4.42	6%	124.1°
2047-06-21 Fri	21	—	unknown	23:15–23:45 (good, 0.5 h)	50.1° 19:55	4.42	2%	112.2°
2047-06-22 Sat	19	—	unknown	23:15–23:40 (good, 0.42 h)	50.1° 19:50	4.42	0%	100.1°
2047-06-23 Sun	18	—	unknown	23:15–23:35 (good, 0.33 h)	50.1° 19:45	4.43	0%	87.8°
2047-06-24 Mon	16	—	unknown	23:15–23:35 (good, 0.33 h)	50.1° 19:40	4.44	2%	75.2°
2047-06-25 Tue	14	—	unknown	23:15–23:30 (good, 0.25 h)	50.1° 19:40	4.44	6%	62.5°
2047-06-26 Wed	13	—	unknown	23:15–23:25 (good, 0.17 h)	50.1° 19:35	4.45	13%	49.6°
2047-06-27 Thu	10	—	unknown	22:20–23:50 (marginal, 1.5 h)	50.1° 19:30	4.47	21%	36.6°
2047-06-28 Fri	8	—	unknown	22:20–23:05 (marginal, 0.75 h)	50.1° 19:25	4.48	30%	23.9°
2047-06-29 Sat	7	—	unknown	23:10–23:40 (marginal, 0.5 h)	50.1° 19:20	4.5	41%	12.8°
2047-06-30 Sun	5	—	unknown	23:10–23:40 (marginal, 0.5 h)	50.1° 19:20	4.52	52%	11.6°
2047-07-01 Mon	4	—	unknown	23:10–23:25 (marginal, 0.25 h)	50.1° 19:15	4.54	64%	22.4°
2047-07-02 Tue	3	—	unknown	23:10–23:20 (marginal, 0.17 h)	50.1° 19:10	4.56	74%	35.8°
2047-07-03 Wed	2	—	unknown	23:10–23:15 (marginal, 0.08 h)	50.1° 19:05	4.58	84%	49.8°
2047-07-04 Thu	2	—	unknown	23:10–23:15 (marginal, 0.08 h)	50.1° 19:00	4.61	92%	64.0°
2047-07-05 Fri	2	—	unknown	23:10–23:15 (marginal, 0.08 h)	50.1° 19:00	4.64	97%	78.2°
2047-07-06 Sat	2	—	unknown	23:10–23:15 (marginal, 0.08 h)	50.1° 18:55	4.67	100%	92.3°
2047-07-07 Sun	2	—	unknown	22:15–22:25 (marginal, 0.17 h)	50.1° 18:50	4.7	100%	106.2°
2047-07-08 Mon	3	—	unknown	22:15–22:30 (marginal, 0.25 h)	50.1° 18:45	4.73	97%	119.7°
2047-07-09 Tue	3	—	unknown	22:15–22:25 (marginal, 0.17 h)	50.1° 18:45	4.76	92%	132.8°
2047-07-10 Wed	2	—	unknown	22:15–22:30 (marginal, 0.25 h)	50.1° 18:40	4.8	86%	145.4°
2047-07-11 Thu	2	—	unknown	22:15–22:25 (marginal, 0.17 h)	50.1° 18:35	4.83	78%	157.2°
2047-07-12 Fri	2	—	unknown	22:15–22:20 (marginal, 0.08 h)	50.1° 18:30	4.87	70%	167.1°
2047-07-13 Sat	2	—	unknown	22:15–22:20 (marginal, 0.08 h)	50.1° 18:25	4.91	60%	169.3°
2047-07-14 Sun	2	—	unknown	22:10–22:15 (marginal, 0.08 h)	50.1° 18:25	4.95	51%	161.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-06-15&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.