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: 01-15 (100), 01-16 (100), 01-17 (100), 01-18 (100), 01-19 (100) — by astronomy; check the weather when the night is within four days.

2036-01-12astronomy score per night — click a bar for that night2036-02-10

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-01-12 Sat	36	—	unknown	18:55–00:25 (marginal, 5.5 h)	72.5° 20:40	11.29	100%	45.5°
2036-01-13 Sun	59	—	unknown	18:55–19:45 (good, 0.83 h)	72.5° 20:40	11.28	100%	60.5°
2036-01-14 Mon	76	—	unknown	18:55–22:55 (good, 4.0 h)	72.5° 20:35	11.26	97%	75.5°
2036-01-15 Tue	100	—	unknown	18:55–00:35 (good, 5.67 h)	72.5° 20:30	11.23	91%	90.3°
2036-01-16 Wed	100	—	unknown	18:55–01:20 (good, 6.42 h)	72.5° 20:25	11.21	83%	104.6°
2036-01-17 Thu	100	—	unknown	19:00–01:25 (good, 6.42 h)	72.5° 20:25	11.19	74%	118.5°
2036-01-18 Fri	100	—	unknown	19:00–01:25 (good, 6.42 h)	72.5° 20:20	11.17	64%	131.8°
2036-01-19 Sat	100	—	unknown	19:00–01:20 (good, 6.33 h)	72.5° 20:15	11.14	54%	144.6°
2036-01-20 Sun	100	—	unknown	19:00–01:20 (good, 6.33 h)	72.5° 20:10	11.12	43%	156.6°
2036-01-21 Mon	100	—	unknown	19:00–01:20 (good, 6.33 h)	72.5° 20:05	11.09	34%	166.9°
2036-01-22 Tue	100	—	unknown	19:05–01:15 (good, 6.17 h)	72.5° 20:05	11.07	25%	170.2°
2036-01-23 Wed	100	—	unknown	19:05–01:10 (good, 6.08 h)	72.5° 20:00	11.04	17%	162.4°
2036-01-24 Thu	100	—	unknown	19:05–01:05 (good, 6.0 h)	72.5° 19:55	11.01	11%	151.6°
2036-01-25 Fri	100	—	unknown	19:05–01:00 (good, 5.92 h)	72.5° 19:50	10.98	6%	140.3°
2036-01-26 Sat	100	—	unknown	19:05–01:00 (good, 5.92 h)	72.5° 19:45	10.96	2%	128.8°
2036-01-27 Sun	100	—	unknown	19:10–00:55 (good, 5.75 h)	72.5° 19:45	10.93	0%	117.2°
2036-01-28 Mon	100	—	unknown	19:10–00:50 (good, 5.67 h)	72.5° 19:40	10.9	0%	105.5°
2036-01-29 Tue	100	—	unknown	19:10–00:45 (good, 5.58 h)	72.5° 19:35	10.87	2%	93.7°
2036-01-30 Wed	100	—	unknown	19:10–00:40 (good, 5.5 h)	72.5° 19:30	10.84	6%	81.8°
2036-01-31 Thu	100	—	unknown	19:15–00:40 (good, 5.42 h)	72.5° 19:25	10.8	11%	69.7°
2036-02-01 Fri	99	—	unknown	19:15–00:35 (good, 5.33 h)	72.5° 19:25	10.77	18%	57.6°
2036-02-02 Sat	91	—	unknown	19:15–00:30 (good, 5.25 h)	72.5° 19:20	10.74	26%	45.2°
2036-02-03 Sun	83	—	unknown	19:15–00:25 (good, 5.17 h)	72.5° 19:15	10.7	36%	32.8°
2036-02-04 Mon	68	—	unknown	19:15–00:00 (good, 4.75 h)	72.5° 19:10	10.67	46%	20.6°
2036-02-05 Tue	48	—	unknown	21:05–21:15 (good, 0.17 h)	72.5° 19:10	10.64	57%	10.6°
2036-02-06 Wed	33	—	unknown	19:20–00:30 (marginal, 5.17 h)	72.5° 19:05	10.6	68%	13.0°
2036-02-07 Thu	22	—	unknown	19:20–00:10 (marginal, 4.83 h)	72.5° 19:00	10.57	78%	25.1°
2036-02-08 Fri	21	—	unknown	19:20–23:50 (marginal, 4.5 h)	72.5° 18:55	10.53	87%	39.0°
2036-02-09 Sat	27	—	unknown	19:25–23:50 (marginal, 4.42 h)	72.5° 18:50	10.49	94%	53.6°
2036-02-10 Sun	39	—	unknown	19:25–19:30 (good, 0.08 h)	72.5° 18:50	10.46	98%	68.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-01-12&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.