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: 07-17 (100), 07-18 (100), 07-19 (100), 07-20 (100), 07-21 (100) — by astronomy; check the weather when the night is within four days.

2034-07-05astronomy score per night — click a bar for that night2034-08-03

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-05 Wed	29	—	unknown	00:35–03:50 (marginal, 3.25 h)	89.7° 07:10	4.64	82%	59.2°
2034-07-06 Thu	30	—	unknown	00:30–03:50 (marginal, 3.33 h)	89.8° 07:05	4.67	73%	49.9°
2034-07-07 Fri	35	—	unknown	02:25–03:50 (good, 1.42 h)	89.7° 07:00	4.7	63%	42.1°
2034-07-08 Sat	43	—	unknown	01:20–03:50 (good, 2.5 h)	89.6° 06:55	4.73	52%	37.0°
2034-07-09 Sun	59	—	unknown	00:50–03:50 (good, 3.0 h)	89.6° 06:55	4.77	40%	36.1°
2034-07-10 Mon	71	—	unknown	00:45–03:55 (good, 3.17 h)	89.7° 06:50	4.8	29%	39.8°
2034-07-11 Tue	79	—	unknown	00:40–03:55 (good, 3.25 h)	89.8° 06:45	4.84	19%	47.2°
2034-07-12 Wed	89	—	unknown	00:35–03:55 (good, 3.33 h)	89.7° 06:40	4.88	11%	56.9°
2034-07-13 Thu	92	—	unknown	00:35–03:55 (good, 3.33 h)	89.5° 06:35	4.92	5%	67.7°
2034-07-14 Fri	96	—	unknown	00:30–04:00 (good, 3.5 h)	89.6° 06:35	4.96	1%	79.2°
2034-07-15 Sat	97	—	unknown	00:25–04:00 (good, 3.58 h)	89.7° 06:30	5.0	0%	90.7°
2034-07-16 Sun	99	—	unknown	00:20–04:00 (good, 3.67 h)	89.7° 06:25	5.04	2%	102.0°
2034-07-17 Mon	100	—	unknown	00:20–04:05 (good, 3.75 h)	89.6° 06:20	5.09	6%	112.8°
2034-07-18 Tue	100	—	unknown	00:15–04:05 (good, 3.83 h)	89.5° 06:20	5.13	12%	122.7°
2034-07-19 Wed	100	—	unknown	00:10–04:05 (good, 3.92 h)	89.7° 06:15	5.18	19%	131.3°
2034-07-20 Thu	100	—	unknown	00:05–04:05 (good, 4.0 h)	89.8° 06:10	5.23	28%	138.3°
2034-07-21 Fri	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.7° 06:05	5.28	37%	142.7°
2034-07-22 Sat	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:00	5.33	47%	144.0°
2034-07-23 Sun	100	—	unknown	00:00–04:10 (good, 4.17 h)	89.6° 06:00	5.38	56%	141.9°
2034-07-24 Mon	100	—	unknown	23:55–04:15 (good, 4.33 h)	89.7° 05:55	5.43	65%	137.0°
2034-07-25 Tue	100	—	unknown	23:55–04:15 (good, 4.33 h)	89.8° 05:50	5.48	74%	130.2°
2034-07-26 Wed	100	—	unknown	23:50–04:15 (good, 4.42 h)	89.7° 05:45	5.53	82%	122.0°
2034-07-27 Thu	100	—	unknown	23:55–04:20 (good, 4.42 h)	89.5° 05:40	5.58	89%	112.9°
2034-07-28 Fri	87	—	unknown	00:00–04:20 (good, 4.33 h)	89.6° 05:40	5.63	94%	103.2°
2034-07-29 Sat	78	—	unknown	00:10–04:20 (good, 4.17 h)	89.7° 05:35	5.69	98%	93.0°
2034-07-30 Sun	64	—	unknown	01:20–04:20 (good, 3.0 h)	89.7° 05:30	5.74	100%	82.6°
2034-07-31 Mon	53	—	unknown	02:35–04:25 (good, 1.83 h)	89.6° 05:25	5.8	99%	72.2°
2034-08-01 Tue	44	—	unknown	22:55–04:25 (marginal, 5.5 h)	89.5° 05:25	5.85	97%	61.9°
2034-08-02 Wed	38	—	unknown	22:50–04:25 (marginal, 5.58 h)	89.7° 05:20	5.91	92%	52.2°
2034-08-03 Thu	39	—	unknown	22:45–04:30 (marginal, 5.75 h)	89.8° 05:15	5.96	85%	43.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-05&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.