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: 09-16 (100), 09-17 (100), 09-18 (100), 09-19 (100), 09-20 (100) — by astronomy; check the weather when the night is within four days.

2036-09-15astronomy score per night — click a bar for that night2036-10-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-09-15 Mon	92	—	unknown	00:20–05:30 (good, 5.17 h)	72.5° 05:25	8.4	23%	56.8°
2036-09-16 Tue	100	—	unknown	00:15–05:30 (good, 5.25 h)	72.5° 05:25	8.45	14%	71.2°
2036-09-17 Wed	100	—	unknown	00:15–05:35 (good, 5.33 h)	72.5° 05:20	8.51	7%	85.9°
2036-09-18 Thu	100	—	unknown	00:10–05:35 (good, 5.42 h)	72.5° 05:15	8.56	2%	100.6°
2036-09-19 Fri	100	—	unknown	00:05–05:35 (good, 5.5 h)	72.5° 05:10	8.61	0%	115.3°
2036-09-20 Sat	100	—	unknown	00:00–05:35 (good, 5.58 h)	72.5° 05:05	8.66	1%	129.8°
2036-09-21 Sun	100	—	unknown	00:00–05:40 (good, 5.67 h)	72.5° 05:05	8.71	5%	143.8°
2036-09-22 Mon	100	—	unknown	23:55–05:40 (good, 5.75 h)	72.5° 05:00	8.76	11%	157.0°
2036-09-23 Tue	100	—	unknown	23:50–05:40 (good, 5.83 h)	72.5° 04:55	8.81	19%	168.2°
2036-09-24 Wed	100	—	unknown	23:45–05:40 (good, 5.92 h)	72.5° 04:50	8.86	27%	169.4°
2036-09-25 Thu	100	—	unknown	23:40–05:45 (good, 6.08 h)	72.5° 04:50	8.91	37%	159.7°
2036-09-26 Fri	100	—	unknown	23:40–05:45 (good, 6.08 h)	72.5° 04:45	8.96	47%	148.2°
2036-09-27 Sat	100	—	unknown	23:40–05:45 (good, 6.08 h)	72.5° 04:40	9.01	56%	136.5°
2036-09-28 Sun	100	—	unknown	23:35–05:45 (good, 6.17 h)	72.5° 04:35	9.06	66%	124.8°
2036-09-29 Mon	100	—	unknown	23:35–05:45 (good, 6.17 h)	72.5° 04:30	9.11	74%	113.1°
2036-09-30 Tue	100	—	unknown	23:40–05:50 (good, 6.17 h)	72.5° 04:30	9.16	82%	101.5°
2036-10-01 Wed	100	—	unknown	23:50–05:50 (good, 6.0 h)	72.5° 04:25	9.21	89%	89.7°
2036-10-02 Thu	100	—	unknown	01:05–05:50 (good, 4.75 h)	72.5° 04:20	9.25	94%	77.9°
2036-10-03 Fri	72	—	unknown	02:55–05:50 (good, 2.92 h)	72.5° 04:15	9.3	98%	65.9°
2036-10-04 Sat	55	—	unknown	05:30–05:55 (good, 0.42 h)	72.5° 04:10	9.35	100%	53.8°
2036-10-05 Sun	36	—	unknown	23:20–05:55 (marginal, 6.58 h)	72.5° 04:10	9.4	100%	41.6°
2036-10-06 Mon	23	—	unknown	03:35–05:55 (marginal, 2.33 h)	72.5° 04:05	9.44	98%	29.4°
2036-10-07 Tue	23	—	unknown	23:05–05:55 (marginal, 6.83 h)	72.5° 04:00	9.49	93%	17.6°
2036-10-08 Wed	29	—	unknown	22:45–05:55 (marginal, 7.17 h)	72.5° 03:55	9.53	87%	9.2°
2036-10-09 Thu	40	—	unknown	22:30–06:00 (marginal, 7.5 h)	72.5° 03:55	9.58	79%	14.3°
2036-10-10 Fri	56	—	unknown	22:15–06:00 (marginal, 7.75 h)	72.5° 03:50	9.63	70%	26.2°
2036-10-11 Sat	81	—	unknown	22:40–04:50 (good, 6.17 h)	72.5° 03:45	9.67	59%	39.3°
2036-10-12 Sun	89	—	unknown	22:35–06:00 (good, 7.42 h)	72.5° 03:40	9.71	48%	52.9°
2036-10-13 Mon	98	—	unknown	22:30–06:05 (good, 7.58 h)	72.5° 03:35	9.76	37%	66.8°
2036-10-14 Tue	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:35	9.8	26%	80.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-09-15&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.