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 Seven Sisters: 08-27 (60), 08-16 (59), 08-15 (58), 08-13 (57), 08-14 (57) — by astronomy; check the weather when the night is within four days.

2035-07-29astronomy score per night — click a bar for that night2035-08-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-07-29 Sun	18	—	unknown	03:50–04:20 (good, 0.5 h)	72.5° 08:40	5.67	30%	9.3°
2035-07-30 Mon	22	—	unknown	03:35–04:20 (good, 0.75 h)	72.5° 08:35	5.73	20%	17.8°
2035-07-31 Tue	26	—	unknown	03:25–04:25 (good, 1.0 h)	72.5° 08:30	5.78	11%	31.2°
2035-08-01 Wed	30	—	unknown	03:20–04:25 (good, 1.08 h)	72.5° 08:25	5.84	5%	45.6°
2035-08-02 Thu	32	—	unknown	03:15–04:25 (good, 1.17 h)	72.5° 08:25	5.89	1%	60.2°
2035-08-03 Fri	35	—	unknown	03:15–04:30 (good, 1.25 h)	72.5° 08:20	5.95	0%	74.9°
2035-08-04 Sat	37	—	unknown	03:10–04:30 (good, 1.33 h)	72.5° 08:15	6.0	2%	89.3°
2035-08-05 Sun	38	—	unknown	03:05–04:30 (good, 1.42 h)	72.5° 08:10	6.06	7%	103.4°
2035-08-06 Mon	41	—	unknown	03:00–04:35 (good, 1.58 h)	72.5° 08:05	6.12	13%	117.1°
2035-08-07 Tue	43	—	unknown	03:00–04:35 (good, 1.58 h)	72.5° 08:05	6.17	22%	130.2°
2035-08-08 Wed	45	—	unknown	02:55–04:35 (good, 1.67 h)	72.5° 08:00	6.23	31%	142.8°
2035-08-09 Thu	48	—	unknown	02:50–04:40 (good, 1.83 h)	72.5° 07:55	6.29	40%	154.8°
2035-08-10 Fri	49	—	unknown	02:45–04:40 (good, 1.92 h)	72.5° 07:50	6.34	50%	165.4°
2035-08-11 Sat	51	—	unknown	02:40–04:40 (good, 2.0 h)	72.5° 07:50	6.4	60%	170.6°
2035-08-12 Sun	55	—	unknown	02:40–04:45 (good, 2.08 h)	72.5° 07:45	6.46	69%	164.3°
2035-08-13 Mon	57	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:40	6.52	77%	153.8°
2035-08-14 Tue	57	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:35	6.57	85%	142.6°
2035-08-15 Wed	58	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:30	6.63	91%	131.0°
2035-08-16 Thu	59	—	unknown	02:30–04:50 (good, 2.33 h)	72.5° 07:30	6.69	96%	119.3°
2035-08-17 Fri	48	—	unknown	02:35–04:50 (good, 2.25 h)	72.5° 07:25	6.75	99%	107.3°
2035-08-18 Sat	40	—	unknown	02:50–04:50 (good, 2.0 h)	72.5° 07:20	6.8	100%	95.1°
2035-08-19 Sun	33	—	unknown	03:50–04:55 (good, 1.08 h)	72.5° 07:15	6.86	99%	82.7°
2035-08-20 Mon	27	—	unknown	01:55–04:55 (marginal, 3.0 h)	72.5° 07:10	6.92	96%	70.2°
2035-08-21 Tue	21	—	unknown	01:55–04:55 (marginal, 3.0 h)	72.5° 07:10	6.98	91%	57.4°
2035-08-22 Wed	19	—	unknown	01:55–05:00 (marginal, 3.08 h)	72.5° 07:05	7.03	85%	44.5°
2035-08-23 Thu	18	—	unknown	01:50–05:00 (marginal, 3.17 h)	72.5° 07:00	7.09	76%	31.6°
2035-08-24 Fri	24	—	unknown	01:35–05:00 (marginal, 3.42 h)	72.5° 06:55	7.15	66%	19.1°
2035-08-25 Sat	34	—	unknown	04:40–05:00 (good, 0.33 h)	72.5° 06:55	7.21	55%	9.8°
2035-08-26 Sun	46	—	unknown	02:05–05:05 (good, 3.0 h)	72.5° 06:50	7.26	44%	14.5°
2035-08-27 Mon	60	—	unknown	01:50–05:05 (good, 3.25 h)	72.5° 06:45	7.32	32%	26.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-07-29&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.