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: 05-20 (100), 05-21 (100), 05-22 (100), 05-23 (100), 05-24 (100) — by astronomy; check the weather when the night is within four days.

2033-05-16astronomy score per night — click a bar for that night2033-06-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-05-16 Mon	56	—	unknown	01:25–02:05 (good, 0.67 h)	87.1° 04:20	5.51	94%	58.9°
2033-05-17 Tue	84	—	unknown	22:35–04:05 (good, 5.5 h)	87.1° 04:15	5.46	87%	56.9°
2033-05-18 Wed	89	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:10	5.41	80%	56.8°
2033-05-19 Thu	95	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.35	70%	58.7°
2033-05-20 Fri	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:05	5.3	60%	62.5°
2033-05-21 Sat	100	—	unknown	22:40–04:00 (good, 5.33 h)	87.1° 04:00	5.26	48%	67.9°
2033-05-22 Sun	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:55	5.21	37%	74.6°
2033-05-23 Mon	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:50	5.16	26%	82.1°
2033-05-24 Tue	100	—	unknown	22:45–03:55 (good, 5.17 h)	87.1° 03:45	5.11	16%	90.0°
2033-05-25 Wed	100	—	unknown	22:50–03:55 (good, 5.08 h)	87.1° 03:45	5.07	9%	98.0°
2033-05-26 Thu	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:40	5.02	3%	105.6°
2033-05-27 Fri	100	—	unknown	22:50–03:50 (good, 5.0 h)	87.1° 03:35	4.98	0%	112.3°
2033-05-28 Sat	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.94	0%	117.8°
2033-05-29 Sun	100	—	unknown	22:55–03:50 (good, 4.92 h)	87.1° 03:30	4.9	3%	121.5°
2033-05-30 Mon	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:25	4.86	8%	123.3°
2033-05-31 Tue	100	—	unknown	22:55–03:45 (good, 4.83 h)	87.1° 03:20	4.82	14%	123.0°
2033-06-01 Wed	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:15	4.79	22%	120.8°
2033-06-02 Thu	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.75	31%	117.2°
2033-06-03 Fri	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:10	4.72	40%	112.5°
2033-06-04 Sat	100	—	unknown	23:00–03:45 (good, 4.75 h)	87.1° 03:05	4.68	50%	107.0°
2033-06-05 Sun	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 03:00	4.65	59%	100.9°
2033-06-06 Mon	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:55	4.63	68%	94.6°
2033-06-07 Tue	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.6	76%	88.0°
2033-06-08 Wed	100	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:50	4.57	84%	81.5°
2033-06-09 Thu	76	—	unknown	23:05–03:40 (good, 4.58 h)	87.1° 02:45	4.55	91%	75.1°
2033-06-10 Fri	64	—	unknown	23:35–03:40 (good, 4.08 h)	87.1° 02:40	4.53	96%	69.2°
2033-06-11 Sat	55	—	unknown	01:50–03:40 (good, 1.83 h)	87.1° 02:35	4.51	99%	64.0°
2033-06-12 Sun	48	—	unknown	23:10–04:30 (marginal, 5.33 h)	87.1° 02:35	4.49	100%	59.9°
2033-06-13 Mon	47	—	unknown	23:10–03:40 (marginal, 4.5 h)	87.1° 02:30	4.48	99%	57.4°
2033-06-14 Tue	53	—	unknown	23:10–00:45 (good, 1.58 h)	87.1° 02:25	4.46	95%	56.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-05-16&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.