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: 08-16 (100), 08-17 (100), 08-18 (100), 08-19 (100), 08-20 (100) — by astronomy; check the weather when the night is within four days.

2036-08-16astronomy score per night — click a bar for that night2036-09-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-08-16 Sat	100	—	unknown	22:20–04:50 (good, 6.5 h)	89.6° 04:20	6.73	30%	60.9°
2036-08-17 Sun	100	—	unknown	22:15–04:50 (good, 6.58 h)	89.5° 04:20	6.79	20%	71.3°
2036-08-18 Mon	100	—	unknown	22:10–04:55 (good, 6.75 h)	89.7° 04:15	6.85	11%	82.5°
2036-08-19 Tue	100	—	unknown	22:05–04:55 (good, 6.83 h)	89.8° 04:10	6.91	5%	94.3°
2036-08-20 Wed	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.7° 04:05	6.96	1%	106.0°
2036-08-21 Thu	100	—	unknown	22:00–04:55 (good, 6.92 h)	89.6° 04:00	7.02	0%	117.3°
2036-08-22 Fri	100	—	unknown	21:55–05:00 (good, 7.08 h)	89.6° 04:00	7.08	2%	127.5°
2036-08-23 Sat	100	—	unknown	21:50–05:00 (good, 7.17 h)	89.7° 03:55	7.13	7%	135.6°
2036-08-24 Sun	100	—	unknown	21:50–05:00 (good, 7.17 h)	89.8° 03:50	7.19	14%	140.6°
2036-08-25 Mon	100	—	unknown	21:50–05:05 (good, 7.25 h)	89.7° 03:45	7.25	23%	141.5°
2036-08-26 Tue	100	—	unknown	21:45–05:05 (good, 7.33 h)	89.5° 03:40	7.31	33%	138.4°
2036-08-27 Wed	100	—	unknown	21:45–05:05 (good, 7.33 h)	89.6° 03:40	7.36	43%	132.5°
2036-08-28 Thu	100	—	unknown	21:40–05:05 (good, 7.42 h)	89.8° 03:35	7.42	53%	124.9°
2036-08-29 Fri	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.7° 03:30	7.48	63%	116.3°
2036-08-30 Sat	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.6° 03:25	7.53	72%	107.3°
2036-08-31 Sun	100	—	unknown	21:40–05:10 (good, 7.5 h)	89.5° 03:25	7.59	80%	98.1°
2036-09-01 Mon	100	—	unknown	21:45–05:15 (good, 7.5 h)	89.7° 03:20	7.64	87%	88.8°
2036-09-02 Tue	100	—	unknown	22:45–05:15 (good, 6.5 h)	89.8° 03:15	7.7	93%	79.6°
2036-09-03 Wed	75	—	unknown	00:10–05:15 (good, 5.08 h)	89.7° 03:10	7.75	97%	70.5°
2036-09-04 Thu	66	—	unknown	03:40–05:15 (good, 1.58 h)	89.6° 03:05	7.81	99%	61.7°
2036-09-05 Fri	58	—	unknown	21:25–05:20 (marginal, 7.92 h)	89.6° 03:05	7.86	100%	53.6°
2036-09-06 Sat	50	—	unknown	21:25–05:20 (marginal, 7.92 h)	89.7° 03:00	7.92	99%	46.5°
2036-09-07 Sun	48	—	unknown	21:20–05:20 (marginal, 8.0 h)	89.8° 02:55	7.97	96%	41.2°
2036-09-08 Mon	80	—	unknown	21:20–21:25 (good, 0.08 h)	89.7° 02:50	8.03	91%	38.4°
2036-09-09 Tue	84	—	unknown	21:20–21:55 (good, 0.58 h)	89.5° 02:45	8.08	84%	39.0°
2036-09-10 Wed	88	—	unknown	21:15–01:10 (good, 3.92 h)	89.6° 02:45	8.14	76%	42.9°
2036-09-11 Thu	92	—	unknown	21:15–04:25 (good, 7.17 h)	89.8° 02:40	8.19	66%	49.5°
2036-09-12 Fri	98	—	unknown	21:10–05:25 (good, 8.25 h)	89.8° 02:35	8.24	56%	58.0°
2036-09-13 Sat	100	—	unknown	21:10–05:30 (good, 8.33 h)	89.6° 02:30	8.3	44%	67.8°
2036-09-14 Sun	100	—	unknown	21:10–05:30 (good, 8.33 h)	89.5° 02:30	8.35	34%	78.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-08-16&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.