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: 09-30 (100), 10-01 (100), 10-02 (100), 10-03 (100), 10-04 (100) — by astronomy; check the weather when the night is within four days.

2033-09-30astronomy score per night — click a bar for that night2033-10-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-30 Fri	100	—	unknown	23:25–05:50 (good, 6.42 h)	72.5° 04:30	9.15	42%	149.3°
2033-10-01 Sat	100	—	unknown	23:25–05:50 (good, 6.42 h)	72.5° 04:25	9.19	52%	136.9°
2033-10-02 Sun	100	—	unknown	23:20–05:50 (good, 6.5 h)	72.5° 04:20	9.24	63%	124.0°
2033-10-03 Mon	100	—	unknown	23:20–05:50 (good, 6.5 h)	72.5° 04:15	9.29	73%	110.6°
2033-10-04 Tue	100	—	unknown	23:30–05:50 (good, 6.33 h)	72.5° 04:15	9.34	83%	96.6°
2033-10-05 Wed	100	—	unknown	00:25–05:55 (good, 5.5 h)	72.5° 04:10	9.38	91%	82.3°
2033-10-06 Thu	100	—	unknown	02:25–05:55 (good, 3.5 h)	72.5° 04:05	9.43	96%	67.5°
2033-10-07 Fri	54	—	unknown	05:45–05:55 (good, 0.17 h)	72.5° 04:00	9.48	100%	52.5°
2033-10-08 Sat	31	—	unknown	01:00–05:55 (marginal, 4.92 h)	72.5° 04:00	9.52	100%	37.5°
2033-10-09 Sun	22	—	unknown	04:10–06:00 (marginal, 1.83 h)	72.5° 03:55	9.57	97%	22.9°
2033-10-10 Mon	25	—	unknown	22:45–06:00 (marginal, 7.25 h)	72.5° 03:50	9.61	91%	10.3°
2033-10-11 Tue	36	—	unknown	22:25–06:00 (marginal, 7.58 h)	72.5° 03:45	9.66	83%	11.3°
2033-10-12 Wed	52	—	unknown	22:10–06:00 (marginal, 7.83 h)	72.5° 03:40	9.7	74%	23.5°
2033-10-13 Thu	81	—	unknown	22:30–03:10 (good, 4.67 h)	72.5° 03:40	9.75	63%	36.7°
2033-10-14 Fri	88	—	unknown	22:30–06:05 (good, 7.58 h)	72.5° 03:35	9.79	53%	49.6°
2033-10-15 Sat	96	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:30	9.83	43%	62.3°
2033-10-16 Sun	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.88	33%	74.6°
2033-10-17 Mon	100	—	unknown	22:15–06:05 (good, 7.83 h)	72.5° 03:20	9.92	24%	86.8°
2033-10-18 Tue	100	—	unknown	22:10–06:10 (good, 8.0 h)	72.5° 03:20	9.96	16%	98.7°
2033-10-19 Wed	100	—	unknown	22:10–06:10 (good, 8.0 h)	72.5° 03:15	10.0	10%	110.5°
2033-10-20 Thu	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:10	10.05	5%	122.3°
2033-10-21 Fri	100	—	unknown	22:00–06:10 (good, 8.17 h)	72.5° 03:05	10.09	2%	133.9°
2033-10-22 Sat	100	—	unknown	21:55–06:10 (good, 8.25 h)	72.5° 03:05	10.13	0%	145.4°
2033-10-23 Sun	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 03:00	10.17	0%	156.8°
2033-10-24 Mon	100	—	unknown	21:50–06:15 (good, 8.42 h)	72.5° 02:55	10.21	2%	167.3°
2033-10-25 Tue	100	—	unknown	21:45–06:15 (good, 8.5 h)	72.5° 02:50	10.25	6%	171.8°
2033-10-26 Wed	100	—	unknown	21:40–06:15 (good, 8.58 h)	72.5° 02:45	10.29	12%	163.7°
2033-10-27 Thu	100	—	unknown	21:35–06:15 (good, 8.67 h)	72.5° 02:45	10.33	19%	152.4°
2033-10-28 Fri	100	—	unknown	21:35–06:20 (good, 8.75 h)	72.5° 02:40	10.36	27%	140.3°
2033-10-29 Sat	100	—	unknown	21:30–05:20 (good, 8.83 h)	72.5° 02:35	10.4	37%	127.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-30&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.