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 HD 189733: 02-11 (5), 02-12 (5), 02-08 (4), 02-09 (4), 02-10 (4) — by astronomy; check the weather when the night is within four days.

2036-01-14astronomy score per night — click a bar for that night2036-02-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-01-14 Mon	0	—	unknown	—	71.1° 12:50	11.26	97%	138.5°
2036-01-15 Tue	0	—	unknown	—	71.1° 12:45	11.23	91%	133.4°
2036-01-16 Wed	0	—	unknown	—	71.1° 12:40	11.21	83%	125.6°
2036-01-17 Thu	0	—	unknown	—	71.1° 12:40	11.19	74%	116.4°
2036-01-18 Fri	0	—	unknown	—	71.1° 12:35	11.17	64%	106.7°
2036-01-19 Sat	0	—	unknown	—	71.1° 12:30	11.14	54%	96.8°
2036-01-20 Sun	0	—	unknown	—	71.1° 12:25	11.12	43%	87.1°
2036-01-21 Mon	0	—	unknown	—	71.1° 12:20	11.09	34%	77.7°
2036-01-22 Tue	0	—	unknown	—	71.1° 12:20	11.07	25%	68.8°
2036-01-23 Wed	0	—	unknown	—	71.1° 12:15	11.04	17%	60.4°
2036-01-24 Thu	0	—	unknown	—	71.1° 12:10	11.01	11%	53.0°
2036-01-25 Fri	0	—	unknown	—	71.1° 12:05	10.98	6%	46.7°
2036-01-26 Sat	0	—	unknown	—	71.1° 12:00	10.96	2%	42.4°
2036-01-27 Sun	0	—	unknown	—	71.1° 11:55	10.93	0%	40.5°
2036-01-28 Mon	1	—	unknown	—	71.1° 11:50	10.9	0%	41.4°
2036-01-29 Tue	1	—	unknown	—	71.1° 11:45	10.87	2%	45.0°
2036-01-30 Wed	1	—	unknown	—	71.1° 11:40	10.84	6%	50.7°
2036-01-31 Thu	1	—	unknown	—	71.1° 11:40	10.8	11%	58.1°
2036-02-01 Fri	1	—	unknown	—	71.1° 11:35	10.77	18%	66.5°
2036-02-02 Sat	1	—	unknown	—	71.1° 11:30	10.74	26%	75.6°
2036-02-03 Sun	2	—	unknown	06:25–06:30 (marginal, 0.08 h)	71.1° 11:25	10.7	36%	85.3°
2036-02-04 Mon	2	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:25	10.67	46%	95.3°
2036-02-05 Tue	3	—	unknown	06:20–06:30 (marginal, 0.17 h)	71.1° 11:20	10.64	57%	105.5°
2036-02-06 Wed	3	—	unknown	06:15–06:30 (marginal, 0.25 h)	71.1° 11:15	10.6	68%	115.5°
2036-02-07 Thu	3	—	unknown	06:10–06:25 (marginal, 0.25 h)	71.1° 11:10	10.57	78%	124.9°
2036-02-08 Fri	4	—	unknown	05:40–05:55 (marginal, 0.25 h)	71.1° 11:05	10.53	87%	132.9°
2036-02-09 Sat	4	—	unknown	06:00–06:25 (marginal, 0.42 h)	71.1° 11:05	10.49	94%	138.2°
2036-02-10 Sun	4	—	unknown	05:30–05:50 (marginal, 0.33 h)	71.1° 11:00	10.46	98%	139.5°
2036-02-11 Mon	5	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:55	10.42	100%	136.2°
2036-02-12 Tue	5	—	unknown	05:25–05:50 (marginal, 0.42 h)	71.1° 10:50	10.38	98%	129.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-01-14&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.