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: 01-07 (100), 01-08 (100), 01-09 (100), 01-10 (100), 01-11 (100) — by astronomy; check the weather when the night is within four days.

2035-01-07astronomy score per night — click a bar for that night2035-02-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-07 Sun	100	—	unknown	18:50–02:10 (good, 7.33 h)	72.5° 21:00	11.38	3%	149.7°
2035-01-08 Mon	100	—	unknown	18:50–02:10 (good, 7.33 h)	72.5° 20:55	11.36	1%	138.1°
2035-01-09 Tue	100	—	unknown	18:50–02:05 (good, 7.25 h)	72.5° 20:55	11.34	0%	126.2°
2035-01-10 Wed	100	—	unknown	18:50–02:00 (good, 7.17 h)	72.5° 20:50	11.33	2%	114.1°
2035-01-11 Thu	100	—	unknown	18:50–01:55 (good, 7.08 h)	72.5° 20:45	11.31	5%	101.8°
2035-01-12 Fri	100	—	unknown	18:55–01:50 (good, 6.92 h)	72.5° 20:40	11.29	11%	89.2°
2035-01-13 Sat	100	—	unknown	18:55–01:50 (good, 6.92 h)	72.5° 20:35	11.27	18%	76.5°
2035-01-14 Sun	100	—	unknown	18:55–01:45 (good, 6.83 h)	72.5° 20:35	11.25	26%	63.6°
2035-01-15 Mon	94	—	unknown	18:55–01:40 (good, 6.75 h)	72.5° 20:30	11.23	36%	50.4°
2035-01-16 Tue	85	—	unknown	18:55–01:35 (good, 6.67 h)	72.5° 20:25	11.21	47%	37.2°
2035-01-17 Wed	64	—	unknown	21:05–01:00 (good, 3.92 h)	72.5° 20:20	11.18	58%	24.0°
2035-01-18 Thu	47	—	unknown	19:00–01:50 (marginal, 6.83 h)	72.5° 20:20	11.16	69%	12.1°
2035-01-19 Fri	30	—	unknown	19:00–01:30 (marginal, 6.5 h)	72.5° 20:15	11.14	80%	11.1°
2035-01-20 Sat	22	—	unknown	19:00–01:05 (marginal, 6.08 h)	72.5° 20:10	11.11	88%	22.9°
2035-01-21 Sun	24	—	unknown	19:00–22:55 (marginal, 3.92 h)	72.5° 20:05	11.09	95%	36.9°
2035-01-22 Mon	36	—	unknown	19:05–00:50 (marginal, 5.75 h)	72.5° 20:00	11.06	99%	51.2°
2035-01-23 Tue	55	—	unknown	19:05–20:05 (good, 1.0 h)	72.5° 20:00	11.03	100%	65.6°
2035-01-24 Wed	76	—	unknown	19:05–22:35 (good, 3.5 h)	72.5° 19:55	11.01	98%	79.8°
2035-01-25 Thu	100	—	unknown	19:05–00:05 (good, 5.0 h)	72.5° 19:50	10.98	94%	93.7°
2035-01-26 Fri	100	—	unknown	19:05–00:40 (good, 5.58 h)	72.5° 19:45	10.95	88%	107.2°
2035-01-27 Sat	100	—	unknown	19:10–00:45 (good, 5.58 h)	72.5° 19:40	10.92	81%	120.2°
2035-01-28 Sun	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.5° 19:40	10.89	72%	132.7°
2035-01-29 Mon	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.5° 19:35	10.86	63%	144.8°
2035-01-30 Tue	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.5° 19:30	10.83	53%	156.2°
2035-01-31 Wed	100	—	unknown	19:15–00:35 (good, 5.33 h)	72.5° 19:25	10.8	44%	166.4°
2035-02-01 Thu	100	—	unknown	19:15–00:35 (good, 5.33 h)	72.5° 19:25	10.76	34%	170.7°
2035-02-02 Fri	100	—	unknown	19:15–00:30 (good, 5.25 h)	72.5° 19:20	10.73	26%	163.7°
2035-02-03 Sat	100	—	unknown	19:15–00:25 (good, 5.17 h)	72.5° 19:15	10.7	18%	153.1°
2035-02-04 Sun	100	—	unknown	19:15–00:20 (good, 5.08 h)	72.5° 19:10	10.66	11%	141.7°
2035-02-05 Mon	100	—	unknown	19:20–00:20 (good, 5.0 h)	72.5° 19:05	10.63	6%	129.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-07&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.