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: 01-12 (100), 01-13 (100), 01-14 (100), 01-15 (100), 01-16 (100) — by astronomy; check the weather when the night is within four days.

2034-01-12astronomy score per night — click a bar for that night2034-02-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-01-12 Thu	100	—	unknown	18:55–23:45 (good, 4.83 h)	89.6° 17:35	11.29	46%	144.8°
2034-01-13 Fri	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.5° 17:35	11.27	37%	142.5°
2034-01-14 Sat	100	—	unknown	18:55–23:40 (good, 4.75 h)	89.7° 17:30	11.24	28%	137.3°
2034-01-15 Sun	100	—	unknown	18:55–23:35 (good, 4.67 h)	89.8° 17:25	11.22	20%	130.0°
2034-01-16 Mon	100	—	unknown	18:55–23:30 (good, 4.58 h)	89.7° 17:20	11.2	13%	121.3°
2034-01-17 Tue	100	—	unknown	19:00–23:25 (good, 4.42 h)	89.5° 17:15	11.18	7%	111.7°
2034-01-18 Wed	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.6° 17:15	11.16	3%	101.4°
2034-01-19 Thu	100	—	unknown	19:00–23:20 (good, 4.33 h)	89.7° 17:10	11.13	0%	90.6°
2034-01-20 Fri	100	—	unknown	19:00–23:15 (good, 4.25 h)	89.8° 17:05	11.11	0%	79.6°
2034-01-21 Sat	100	—	unknown	19:00–23:10 (good, 4.17 h)	89.6° 17:00	11.08	3%	68.6°
2034-01-22 Sun	98	—	unknown	19:05–23:05 (good, 4.0 h)	89.5° 17:00	11.05	8%	58.0°
2034-01-23 Mon	94	—	unknown	19:05–23:00 (good, 3.92 h)	89.6° 16:55	11.03	15%	48.3°
2034-01-24 Tue	80	—	unknown	19:05–23:00 (good, 3.92 h)	89.8° 16:50	11.0	24%	40.4°
2034-01-25 Wed	65	—	unknown	19:05–22:40 (good, 3.58 h)	89.7° 16:45	10.97	34%	35.8°
2034-01-26 Thu	49	—	unknown	19:10–22:20 (good, 3.17 h)	89.6° 16:40	10.94	45%	35.8°
2034-01-27 Fri	38	—	unknown	19:10–19:55 (good, 0.75 h)	89.5° 16:40	10.91	57%	40.4°
2034-01-28 Sat	31	—	unknown	19:10–23:05 (marginal, 3.92 h)	89.7° 16:35	10.88	68%	48.1°
2034-01-29 Sun	29	—	unknown	19:10–22:55 (marginal, 3.75 h)	89.8° 16:30	10.85	78%	57.7°
2034-01-30 Mon	30	—	unknown	19:10–22:50 (marginal, 3.67 h)	89.7° 16:25	10.82	86%	68.3°
2034-01-31 Tue	34	—	unknown	19:15–19:45 (good, 0.5 h)	89.5° 16:20	10.79	93%	79.2°
2034-02-01 Wed	41	—	unknown	19:15–20:45 (good, 1.5 h)	89.6° 16:20	10.76	97%	90.2°
2034-02-02 Thu	49	—	unknown	19:15–21:45 (good, 2.5 h)	89.7° 16:15	10.72	100%	101.1°
2034-02-03 Fri	57	—	unknown	19:15–22:00 (good, 2.75 h)	89.8° 16:10	10.69	100%	111.5°
2034-02-04 Sat	63	—	unknown	19:20–22:00 (good, 2.67 h)	89.6° 16:05	10.65	98%	121.3°
2034-02-05 Sun	69	—	unknown	19:20–22:00 (good, 2.67 h)	89.5° 16:00	10.62	94%	130.1°
2034-02-06 Mon	69	—	unknown	19:20–22:00 (good, 2.67 h)	89.6° 16:00	10.58	88%	137.4°
2034-02-07 Tue	68	—	unknown	19:20–22:05 (good, 2.75 h)	89.8° 15:55	10.55	81%	142.5°
2034-02-08 Wed	67	—	unknown	19:20–22:00 (good, 2.67 h)	89.7° 15:50	10.51	73%	144.7°
2034-02-09 Thu	63	—	unknown	19:25–21:55 (good, 2.5 h)	89.6° 15:45	10.47	64%	143.4°
2034-02-10 Fri	62	—	unknown	19:25–21:50 (good, 2.42 h)	89.5° 15:45	10.44	55%	139.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-01-12&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.