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 HD 189733: 06-06 (100), 06-07 (100), 06-08 (100), 06-09 (100), 06-10 (100) — by astronomy; check the weather when the night is within four days.

2029-05-25astronomy score per night — click a bar for that night2029-06-23

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-05-25 Fri	67	—	unknown	00:30–03:55 (good, 3.42 h)	71.1° 05:05	5.07	95%	92.4°
2029-05-26 Sat	55	—	unknown	01:20–03:50 (good, 2.5 h)	71.1° 05:05	5.03	99%	80.9°
2029-05-27 Sun	46	—	unknown	02:15–03:50 (good, 1.58 h)	71.1° 05:00	4.98	100%	69.7°
2029-05-28 Mon	39	—	unknown	03:20–03:50 (good, 0.5 h)	71.1° 04:55	4.94	98%	59.4°
2029-05-29 Tue	36	—	unknown	23:30–03:50 (marginal, 4.33 h)	71.1° 04:50	4.9	94%	50.4°
2029-05-30 Wed	37	—	unknown	23:20–03:45 (marginal, 4.42 h)	71.1° 04:50	4.86	88%	43.6°
2029-05-31 Thu	60	—	unknown	23:40–00:15 (good, 0.58 h)	71.1° 04:45	4.82	80%	39.7°
2029-06-01 Fri	71	—	unknown	23:40–03:45 (good, 4.08 h)	71.1° 04:40	4.79	70%	39.4°
2029-06-02 Sat	81	—	unknown	23:35–03:45 (good, 4.17 h)	71.1° 04:35	4.75	61%	42.3°
2029-06-03 Sun	92	—	unknown	23:30–03:45 (good, 4.25 h)	71.1° 04:30	4.72	51%	47.7°
2029-06-04 Mon	95	—	unknown	23:25–03:45 (good, 4.33 h)	71.1° 04:30	4.68	42%	54.7°
2029-06-05 Tue	98	—	unknown	23:25–03:40 (good, 4.25 h)	71.1° 04:25	4.65	32%	62.7°
2029-06-06 Wed	100	—	unknown	23:20–03:40 (good, 4.33 h)	71.1° 04:20	4.63	24%	71.3°
2029-06-07 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 04:15	4.6	16%	80.3°
2029-06-08 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:10	4.57	10%	89.5°
2029-06-09 Sat	100	—	unknown	23:05–03:40 (good, 4.58 h)	71.1° 04:10	4.55	5%	98.8°
2029-06-10 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	71.1° 04:05	4.53	2%	108.2°
2029-06-11 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 04:00	4.51	0%	117.2°
2029-06-12 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:55	4.49	1%	125.7°
2029-06-13 Wed	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:55	4.48	3%	133.1°
2029-06-14 Thu	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:50	4.46	8%	138.5°
2029-06-15 Fri	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:45	4.45	15%	140.9°
2029-06-16 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:40	4.44	24%	139.5°
2029-06-17 Sun	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	34%	134.6°
2029-06-18 Mon	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:35	4.43	44%	126.9°
2029-06-19 Tue	100	—	unknown	23:10–03:40 (good, 4.5 h)	71.1° 03:30	4.42	56%	117.6°
2029-06-20 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:25	4.42	67%	107.2°
2029-06-21 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:20	4.42	78%	96.2°
2029-06-22 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	71.1° 03:15	4.43	87%	85.0°
2029-06-23 Sat	73	—	unknown	23:45–03:40 (good, 3.92 h)	71.1° 03:15	4.43	94%	73.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-05-25&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.