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: 06-11 (31), 06-10 (30), 06-09 (28), 06-08 (27), 06-07 (23) — by astronomy; check the weather when the night is within four days.

2029-05-13astronomy score per night — click a bar for that night2029-06-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-05-13 Sun	4	—	unknown	04:30–04:55 (marginal, 0.42 h)	89.7° 10:35	5.67	0%	40.9°
2029-05-14 Mon	5	—	unknown	04:30–04:55 (marginal, 0.42 h)	89.5° 10:30	5.62	2%	49.9°
2029-05-15 Tue	5	—	unknown	04:25–04:50 (marginal, 0.42 h)	89.6° 10:30	5.56	5%	59.9°
2029-05-16 Wed	6	—	unknown	04:20–04:50 (marginal, 0.5 h)	89.7° 10:25	5.51	11%	70.6°
2029-05-17 Thu	6	—	unknown	04:15–04:50 (marginal, 0.58 h)	89.7° 10:20	5.46	18%	81.7°
2029-05-18 Fri	7	—	unknown	04:15–04:50 (marginal, 0.58 h)	89.6° 10:15	5.41	26%	93.1°
2029-05-19 Sat	7	—	unknown	04:10–04:45 (marginal, 0.58 h)	89.5° 10:10	5.36	36%	104.7°
2029-05-20 Sun	8	—	unknown	04:05–04:45 (marginal, 0.67 h)	89.6° 10:10	5.31	47%	116.4°
2029-05-21 Mon	9	—	unknown	03:30–04:45 (marginal, 1.25 h)	89.7° 10:05	5.26	58%	127.8°
2029-05-22 Tue	9	—	unknown	03:25–04:45 (marginal, 1.33 h)	89.7° 10:00	5.21	70%	138.5°
2029-05-23 Wed	10	—	unknown	03:20–04:40 (marginal, 1.33 h)	89.6° 09:55	5.16	80%	147.1°
2029-05-24 Thu	11	—	unknown	03:50–03:55 (good, 0.08 h)	89.5° 09:55	5.11	88%	151.4°
2029-05-25 Fri	11	—	unknown	03:10–04:40 (marginal, 1.5 h)	89.7° 09:50	5.07	95%	149.0°
2029-05-26 Sat	10	—	unknown	03:10–04:40 (marginal, 1.5 h)	89.7° 09:45	5.03	99%	141.2°
2029-05-27 Sun	11	—	unknown	03:05–04:40 (marginal, 1.58 h)	89.7° 09:40	4.98	100%	130.6°
2029-05-28 Mon	12	—	unknown	03:45–03:50 (good, 0.08 h)	89.5° 09:35	4.94	98%	118.8°
2029-05-29 Tue	11	—	unknown	02:55–04:35 (marginal, 1.67 h)	89.6° 09:35	4.9	94%	106.7°
2029-05-30 Wed	10	—	unknown	02:50–03:45 (marginal, 0.92 h)	89.7° 09:30	4.86	88%	94.7°
2029-05-31 Thu	10	—	unknown	02:50–03:45 (marginal, 0.92 h)	89.7° 09:25	4.82	80%	83.0°
2029-06-01 Fri	11	—	unknown	02:45–03:45 (marginal, 1.0 h)	89.6° 09:20	4.79	70%	71.7°
2029-06-02 Sat	12	—	unknown	02:40–03:45 (marginal, 1.08 h)	89.5° 09:15	4.75	61%	61.1°
2029-06-03 Sun	14	—	unknown	03:40–03:45 (good, 0.08 h)	89.6° 09:15	4.72	51%	51.1°
2029-06-04 Mon	15	—	unknown	03:30–03:45 (good, 0.25 h)	89.7° 09:10	4.68	42%	42.1°
2029-06-05 Tue	17	—	unknown	03:20–03:40 (good, 0.33 h)	89.7° 09:05	4.65	32%	34.6°
2029-06-06 Wed	20	—	unknown	03:10–03:40 (good, 0.5 h)	89.6° 09:00	4.63	24%	29.7°
2029-06-07 Thu	23	—	unknown	02:55–03:40 (good, 0.75 h)	89.5° 09:00	4.6	16%	28.7°
2029-06-08 Fri	27	—	unknown	02:50–03:40 (good, 0.83 h)	89.7° 08:55	4.57	10%	32.0°
2029-06-09 Sat	28	—	unknown	02:45–03:40 (good, 0.92 h)	89.7° 08:50	4.55	5%	38.6°
2029-06-10 Sun	30	—	unknown	02:40–03:40 (good, 1.0 h)	89.7° 08:45	4.53	2%	47.3°
2029-06-11 Mon	31	—	unknown	02:40–03:40 (good, 1.0 h)	89.5° 08:40	4.51	0%	57.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-05-13&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.