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: 08-21 (77), 08-20 (74), 08-19 (72), 08-18 (69), 08-17 (67) — by astronomy; check the weather when the night is within four days.

2034-07-23astronomy score per night — click a bar for that night2034-08-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-07-23 Sun	13	—	unknown	03:55–04:10 (good, 0.25 h)	72.5° 09:00	5.38	56%	157.1°
2034-07-24 Mon	17	—	unknown	03:50–04:15 (good, 0.42 h)	72.5° 08:55	5.43	65%	167.2°
2034-07-25 Tue	19	—	unknown	03:50–04:15 (good, 0.42 h)	72.5° 08:55	5.48	74%	170.9°
2034-07-26 Wed	20	—	unknown	03:45–04:15 (good, 0.5 h)	72.5° 08:50	5.53	82%	163.2°
2034-07-27 Thu	22	—	unknown	03:40–04:20 (good, 0.67 h)	72.5° 08:45	5.58	89%	152.1°
2034-07-28 Fri	21	—	unknown	03:45–04:20 (good, 0.58 h)	72.5° 08:40	5.63	94%	140.2°
2034-07-29 Sat	21	—	unknown	03:40–04:20 (good, 0.67 h)	72.5° 08:40	5.69	98%	127.9°
2034-07-30 Sun	20	—	unknown	03:40–04:20 (good, 0.67 h)	72.5° 08:35	5.74	100%	115.2°
2034-07-31 Mon	18	—	unknown	03:45–04:25 (good, 0.67 h)	72.5° 08:30	5.8	99%	102.3°
2034-08-01 Tue	16	—	unknown	04:20–04:25 (good, 0.08 h)	72.5° 08:25	5.85	97%	89.0°
2034-08-02 Wed	13	—	unknown	03:00–04:25 (marginal, 1.42 h)	72.5° 08:20	5.91	92%	75.6°
2034-08-03 Thu	12	—	unknown	03:00–04:30 (marginal, 1.5 h)	72.5° 08:20	5.96	85%	62.0°
2034-08-04 Fri	12	—	unknown	02:55–04:30 (marginal, 1.58 h)	72.5° 08:15	6.02	76%	48.3°
2034-08-05 Sat	13	—	unknown	02:50–04:30 (marginal, 1.67 h)	72.5° 08:10	6.07	65%	34.6°
2034-08-06 Sun	17	—	unknown	02:40–04:35 (marginal, 1.92 h)	72.5° 08:05	6.13	54%	21.3°
2034-08-07 Mon	23	—	unknown	03:25–04:35 (good, 1.17 h)	72.5° 08:00	6.19	42%	10.3°
2034-08-08 Tue	31	—	unknown	03:10–04:35 (good, 1.42 h)	72.5° 08:00	6.24	31%	12.5°
2034-08-09 Wed	39	—	unknown	02:55–04:40 (good, 1.75 h)	72.5° 07:55	6.3	21%	24.6°
2034-08-10 Thu	46	—	unknown	02:45–04:40 (good, 1.92 h)	72.5° 07:50	6.36	13%	38.1°
2034-08-11 Fri	51	—	unknown	02:40–04:40 (good, 2.0 h)	72.5° 07:45	6.42	6%	51.8°
2034-08-12 Sat	55	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:45	6.47	2%	65.5°
2034-08-13 Sun	57	—	unknown	02:35–04:45 (good, 2.17 h)	72.5° 07:40	6.53	0%	78.9°
2034-08-14 Mon	59	—	unknown	02:30–04:45 (good, 2.25 h)	72.5° 07:35	6.59	1%	92.1°
2034-08-15 Tue	62	—	unknown	02:25–04:50 (good, 2.42 h)	72.5° 07:30	6.65	4%	105.1°
2034-08-16 Wed	65	—	unknown	02:20–04:50 (good, 2.5 h)	72.5° 07:25	6.7	8%	117.6°
2034-08-17 Thu	67	—	unknown	02:15–04:50 (good, 2.58 h)	72.5° 07:25	6.76	15%	129.9°
2034-08-18 Fri	69	—	unknown	02:15–04:50 (good, 2.58 h)	72.5° 07:20	6.82	22%	141.8°
2034-08-19 Sat	72	—	unknown	02:10–04:55 (good, 2.75 h)	72.5° 07:15	6.88	31%	153.3°
2034-08-20 Sun	74	—	unknown	02:05–04:55 (good, 2.83 h)	72.5° 07:10	6.93	40%	164.0°
2034-08-21 Mon	77	—	unknown	02:00–04:55 (good, 2.92 h)	72.5° 07:05	6.99	49%	171.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-07-23&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.