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: 01-16 (100), 01-17 (100), 01-18 (100), 01-19 (100), 01-20 (100) — by astronomy; check the weather when the night is within four days.

2036-01-16astronomy score per night — click a bar for that night2036-02-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-01-16 Wed	100	—	unknown	18:55–23:20 (good, 4.42 h)	89.6° 17:25	11.21	83%	126.3°
2036-01-17 Thu	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:20	11.19	74%	134.5°
2036-01-18 Fri	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.8° 17:15	11.17	64%	140.1°
2036-01-19 Sat	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.14	54%	142.1°
2036-01-20 Sun	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.5° 17:05	11.12	43%	140.5°
2036-01-21 Mon	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.6° 17:05	11.09	34%	135.8°
2036-01-22 Tue	100	—	unknown	19:05–23:10 (good, 4.08 h)	89.8° 17:00	11.07	25%	129.2°
2036-01-23 Wed	100	—	unknown	19:05–23:05 (good, 4.0 h)	89.7° 16:55	11.04	17%	121.3°
2036-01-24 Thu	100	—	unknown	19:05–23:00 (good, 3.92 h)	89.6° 16:50	11.01	11%	112.7°
2036-01-25 Fri	100	—	unknown	19:05–22:55 (good, 3.83 h)	89.5° 16:50	10.98	6%	103.7°
2036-01-26 Sat	99	—	unknown	19:05–22:55 (good, 3.83 h)	89.7° 16:45	10.96	2%	94.5°
2036-01-27 Sun	96	—	unknown	19:10–22:50 (good, 3.67 h)	89.8° 16:40	10.93	0%	85.1°
2036-01-28 Mon	95	—	unknown	19:10–22:45 (good, 3.58 h)	89.7° 16:35	10.9	0%	75.8°
2036-01-29 Tue	92	—	unknown	19:10–22:40 (good, 3.5 h)	89.6° 16:30	10.87	2%	66.8°
2036-01-30 Wed	88	—	unknown	19:10–22:35 (good, 3.42 h)	89.6° 16:30	10.84	6%	58.1°
2036-01-31 Thu	81	—	unknown	19:15–22:35 (good, 3.33 h)	89.7° 16:25	10.8	11%	50.2°
2036-02-01 Fri	72	—	unknown	19:15–22:30 (good, 3.25 h)	89.8° 16:20	10.77	18%	43.6°
2036-02-02 Sat	62	—	unknown	19:15–22:15 (good, 3.0 h)	89.7° 16:15	10.74	26%	39.2°
2036-02-03 Sun	50	—	unknown	19:15–22:00 (good, 2.75 h)	89.5° 16:10	10.7	36%	38.0°
2036-02-04 Mon	39	—	unknown	19:15–21:40 (good, 2.42 h)	89.6° 16:10	10.67	46%	40.5°
2036-02-05 Tue	31	—	unknown	19:20–19:40 (good, 0.33 h)	89.8° 16:05	10.64	57%	46.3°
2036-02-06 Wed	26	—	unknown	19:20–22:30 (marginal, 3.17 h)	89.8° 16:00	10.6	68%	54.7°
2036-02-07 Thu	24	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.6° 15:55	10.57	78%	64.7°
2036-02-08 Fri	26	—	unknown	19:20–22:20 (marginal, 3.0 h)	89.5° 15:55	10.53	87%	75.8°
2036-02-09 Sat	29	—	unknown	19:25–20:05 (good, 0.67 h)	89.7° 15:50	10.49	94%	87.5°
2036-02-10 Sun	36	—	unknown	19:25–21:05 (good, 1.67 h)	89.8° 15:45	10.46	98%	99.4°
2036-02-11 Mon	43	—	unknown	19:25–21:30 (good, 2.08 h)	89.7° 15:40	10.42	100%	111.0°
2036-02-12 Tue	48	—	unknown	19:25–21:35 (good, 2.17 h)	89.6° 15:35	10.38	98%	121.8°
2036-02-13 Wed	53	—	unknown	19:25–21:30 (good, 2.08 h)	89.6° 15:35	10.34	94%	131.2°
2036-02-14 Thu	52	—	unknown	19:30–21:30 (good, 2.0 h)	89.7° 15:30	10.3	88%	138.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-01-16&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.