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 Vega: 09-17 (100), 09-18 (100), 09-19 (100), 09-20 (100), 09-21 (100) — by astronomy; check the weather when the night is within four days.

2033-09-17astronomy score per night — click a bar for that night2033-10-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-17 Sat	100	—	unknown	21:05–02:10 (good, 5.08 h)	87.1° 20:10	8.49	28%	123.3°
2033-09-18 Sun	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.54	19%	121.4°
2033-09-19 Mon	100	—	unknown	21:00–02:05 (good, 5.08 h)	87.1° 20:05	8.6	12%	117.9°
2033-09-20 Tue	100	—	unknown	21:00–02:00 (good, 5.0 h)	87.1° 20:00	8.65	6%	113.3°
2033-09-21 Wed	100	—	unknown	20:55–01:55 (good, 5.0 h)	87.1° 19:55	8.7	2%	107.9°
2033-09-22 Thu	100	—	unknown	20:55–01:50 (good, 4.92 h)	87.1° 19:50	8.75	0%	101.8°
2033-09-23 Fri	100	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:50	8.8	0%	95.4°
2033-09-24 Sat	100	—	unknown	20:50–01:45 (good, 4.92 h)	87.1° 19:45	8.85	2%	88.9°
2033-09-25 Sun	100	—	unknown	20:50–01:40 (good, 4.83 h)	87.1° 19:40	8.9	5%	82.4°
2033-09-26 Mon	100	—	unknown	20:45–01:35 (good, 4.83 h)	87.1° 19:35	8.95	10%	76.2°
2033-09-27 Tue	100	—	unknown	20:45–01:30 (good, 4.75 h)	87.1° 19:30	9.0	16%	70.3°
2033-09-28 Wed	100	—	unknown	20:45–01:25 (good, 4.67 h)	87.1° 19:30	9.05	24%	65.1°
2033-09-29 Thu	96	—	unknown	20:40–01:25 (good, 4.75 h)	87.1° 19:25	9.1	32%	60.9°
2033-09-30 Fri	90	—	unknown	20:40–01:20 (good, 4.67 h)	87.1° 19:20	9.15	42%	57.9°
2033-10-01 Sat	83	—	unknown	20:35–01:15 (good, 4.67 h)	87.1° 19:15	9.19	52%	56.5°
2033-10-02 Sun	65	—	unknown	20:35–00:50 (good, 4.25 h)	87.1° 19:10	9.24	63%	57.0°
2033-10-03 Mon	55	—	unknown	20:35–23:50 (good, 3.25 h)	87.1° 19:10	9.29	73%	59.6°
2033-10-04 Tue	49	—	unknown	20:30–22:25 (good, 1.92 h)	87.1° 19:05	9.34	83%	64.1°
2033-10-05 Wed	47	—	unknown	20:30–22:05 (good, 1.58 h)	87.1° 19:00	9.38	91%	70.2°
2033-10-06 Thu	50	—	unknown	20:30–22:15 (good, 1.75 h)	87.1° 18:55	9.43	96%	77.6°
2033-10-07 Fri	56	—	unknown	20:25–22:50 (good, 2.42 h)	87.1° 18:55	9.48	100%	85.8°
2033-10-08 Sat	65	—	unknown	20:25–23:35 (good, 3.17 h)	87.1° 18:50	9.52	100%	94.2°
2033-10-09 Sun	76	—	unknown	20:25–00:15 (good, 3.83 h)	87.1° 18:45	9.57	97%	102.4°
2033-10-10 Mon	97	—	unknown	20:20–00:20 (good, 4.0 h)	87.1° 18:40	9.61	91%	109.8°
2033-10-11 Tue	100	—	unknown	20:20–00:25 (good, 4.08 h)	87.1° 18:35	9.66	83%	116.0°
2033-10-12 Wed	100	—	unknown	20:20–00:25 (good, 4.08 h)	87.1° 18:35	9.7	74%	120.5°
2033-10-13 Thu	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:30	9.75	63%	123.0°
2033-10-14 Fri	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:25	9.79	53%	123.5°
2033-10-15 Sat	100	—	unknown	20:15–00:20 (good, 4.08 h)	87.1° 18:20	9.83	43%	122.0°
2033-10-16 Sun	100	—	unknown	20:15–00:15 (good, 4.0 h)	87.1° 18:15	9.88	33%	118.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-17&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.