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: 02-16 (44), 02-17 (37), 02-18 (31), 02-19 (25), 03-02 (22) — by astronomy; check the weather when the night is within four days.

2029-02-16astronomy score per night — click a bar for that night2029-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-02-16 Fri	44	—	unknown	19:30–21:25 (good, 1.92 h)	89.6° 15:20	10.19	11%	34.2°
2029-02-17 Sat	37	—	unknown	19:35–21:15 (good, 1.67 h)	89.7° 15:15	10.15	18%	29.4°
2029-02-18 Sun	31	—	unknown	19:35–21:05 (good, 1.5 h)	89.7° 15:10	10.11	25%	28.6°
2029-02-19 Mon	25	—	unknown	19:35–20:50 (good, 1.25 h)	89.6° 15:05	10.07	34%	32.1°
2029-02-20 Tue	20	—	unknown	19:35–20:00 (good, 0.42 h)	89.5° 15:00	10.03	43%	38.8°
2029-02-21 Wed	17	—	unknown	19:35–21:35 (marginal, 2.0 h)	89.6° 15:00	9.99	53%	47.5°
2029-02-22 Thu	14	—	unknown	19:40–21:25 (marginal, 1.75 h)	89.7° 14:55	9.94	63%	57.6°
2029-02-23 Fri	13	—	unknown	19:40–21:20 (marginal, 1.67 h)	89.7° 14:50	9.9	73%	68.5°
2029-02-24 Sat	14	—	unknown	19:40–21:20 (marginal, 1.67 h)	89.6° 14:45	9.86	82%	80.2°
2029-02-25 Sun	16	—	unknown	19:10–21:20 (marginal, 2.17 h)	89.5° 14:45	9.81	89%	92.4°
2029-02-26 Mon	18	—	unknown	19:45–20:20 (good, 0.58 h)	89.7° 14:40	9.77	95%	105.0°
2029-02-27 Tue	20	—	unknown	19:45–20:30 (good, 0.75 h)	89.7° 14:35	9.72	99%	117.6°
2029-02-28 Wed	21	—	unknown	19:45–20:30 (good, 0.75 h)	89.7° 14:30	9.68	100%	129.9°
2029-03-01 Thu	21	—	unknown	19:45–20:25 (good, 0.67 h)	89.5° 14:25	9.63	98%	140.9°
2029-03-02 Fri	22	—	unknown	19:50–20:30 (good, 0.67 h)	89.6° 14:25	9.59	92%	149.0°
2029-03-03 Sat	21	—	unknown	19:50–20:30 (good, 0.67 h)	89.7° 14:20	9.54	85%	151.5°
2029-03-04 Sun	19	—	unknown	19:50–20:25 (good, 0.58 h)	89.7° 14:15	9.5	76%	147.4°
2029-03-05 Mon	18	—	unknown	19:50–20:20 (good, 0.5 h)	89.6° 14:10	9.45	65%	139.0°
2029-03-06 Tue	16	—	unknown	19:50–20:15 (good, 0.42 h)	89.5° 14:05	9.4	54%	128.7°
2029-03-07 Wed	13	—	unknown	19:55–20:10 (good, 0.25 h)	89.6° 14:05	9.35	44%	117.7°
2029-03-08 Thu	12	—	unknown	19:55–20:10 (good, 0.25 h)	89.7° 14:00	9.31	33%	106.5°
2029-03-09 Fri	10	—	unknown	19:55–20:05 (good, 0.17 h)	89.7° 13:55	9.26	24%	95.3°
2029-03-10 Sat	9	—	unknown	19:55–20:00 (good, 0.08 h)	89.6° 13:50	9.21	16%	84.3°
2029-03-11 Sun	7	—	unknown	20:00–20:30 (marginal, 0.5 h)	89.5° 13:50	9.16	10%	73.5°
2029-03-12 Mon	6	—	unknown	20:00–20:25 (marginal, 0.42 h)	89.6° 13:45	9.11	5%	63.1°
2029-03-13 Tue	5	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.7° 13:40	9.06	2%	53.1°
2029-03-14 Wed	4	—	unknown	20:00–20:20 (marginal, 0.33 h)	89.7° 13:35	9.01	0%	44.0°
2029-03-15 Thu	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	89.5° 13:30	8.96	1%	36.1°
2029-03-16 Fri	3	—	unknown	20:05–20:10 (marginal, 0.08 h)	89.5° 13:30	8.91	3%	30.5°
2029-03-17 Sat	1	—	unknown	—	89.7° 13:25	8.86	7%	28.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-02-16&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.