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 Andromeda Galaxy: 06-03 (22), 06-08 (22), 06-02 (21), 06-04 (21), 06-05 (21) — by astronomy; check the weather when the night is within four days.

2036-05-13astronomy score per night — click a bar for that night2036-06-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-13 Tue	3	—	unknown	04:00–04:10 (marginal, 0.17 h)	89.8° 10:35	5.65	87%	106.6°
2036-05-14 Wed	3	—	unknown	03:55–04:10 (marginal, 0.25 h)	89.7° 10:30	5.6	80%	97.2°
2036-05-15 Thu	3	—	unknown	03:50–04:05 (marginal, 0.25 h)	89.5° 10:25	5.55	72%	87.8°
2036-05-16 Fri	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.6° 10:25	5.49	63%	78.5°
2036-05-17 Sat	4	—	unknown	03:45–04:05 (marginal, 0.33 h)	89.8° 10:20	5.44	54%	69.4°
2036-05-18 Sun	5	—	unknown	03:40–04:00 (marginal, 0.33 h)	89.7° 10:15	5.39	45%	60.6°
2036-05-19 Mon	5	—	unknown	03:35–04:00 (marginal, 0.42 h)	89.6° 10:10	5.34	35%	52.5°
2036-05-20 Tue	7	—	unknown	03:30–04:00 (marginal, 0.5 h)	89.5° 10:10	5.29	26%	45.4°
2036-05-21 Wed	8	—	unknown	04:00–04:45 (marginal, 0.75 h)	89.7° 10:05	5.24	18%	40.2°
2036-05-22 Thu	9	—	unknown	03:25–04:45 (marginal, 1.33 h)	89.8° 10:00	5.19	10%	38.0°
2036-05-23 Fri	10	—	unknown	03:50–03:55 (good, 0.08 h)	89.7° 09:55	5.15	5%	39.6°
2036-05-24 Sat	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.6° 09:50	5.1	1%	45.0°
2036-05-25 Sun	12	—	unknown	03:45–03:50 (good, 0.08 h)	89.6° 09:50	5.06	0%	53.1°
2036-05-26 Mon	13	—	unknown	03:40–03:50 (good, 0.17 h)	89.7° 09:45	5.01	2%	63.1°
2036-05-27 Tue	14	—	unknown	03:35–03:50 (good, 0.25 h)	89.8° 09:40	4.97	6%	74.0°
2036-05-28 Wed	15	—	unknown	03:30–03:50 (good, 0.33 h)	89.7° 09:35	4.93	13%	85.4°
2036-05-29 Thu	16	—	unknown	03:30–03:50 (good, 0.33 h)	89.5° 09:30	4.89	22%	96.9°
2036-05-30 Fri	17	—	unknown	03:25–03:45 (good, 0.33 h)	89.6° 09:30	4.85	33%	108.1°
2036-05-31 Sat	18	—	unknown	03:20–03:45 (good, 0.42 h)	89.8° 09:25	4.81	44%	118.6°
2036-06-01 Sun	19	—	unknown	03:15–03:45 (good, 0.5 h)	89.8° 09:20	4.78	55%	128.0°
2036-06-02 Mon	21	—	unknown	03:15–03:45 (good, 0.5 h)	89.6° 09:15	4.74	66%	135.6°
2036-06-03 Tue	22	—	unknown	03:15–03:45 (good, 0.5 h)	89.5° 09:15	4.71	76%	140.5°
2036-06-04 Wed	21	—	unknown	03:15–03:40 (good, 0.42 h)	89.7° 09:10	4.68	84%	141.9°
2036-06-05 Thu	21	—	unknown	03:10–03:40 (good, 0.5 h)	89.8° 09:05	4.65	91%	139.6°
2036-06-06 Fri	21	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 09:00	4.62	96%	134.2°
2036-06-07 Sat	21	—	unknown	03:05–03:40 (good, 0.58 h)	89.6° 08:55	4.59	99%	126.9°
2036-06-08 Sun	22	—	unknown	03:00–03:40 (good, 0.67 h)	89.6° 08:55	4.57	100%	118.5°
2036-06-09 Mon	20	—	unknown	03:05–03:40 (good, 0.58 h)	89.7° 08:50	4.54	99%	109.5°
2036-06-10 Tue	19	—	unknown	03:05–03:40 (good, 0.58 h)	89.8° 08:45	4.52	96%	100.2°
2036-06-11 Wed	18	—	unknown	03:10–03:40 (good, 0.5 h)	89.7° 08:40	4.5	91%	90.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-13&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.