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: 05-05 (80), 05-08 (80), 05-06 (79), 05-07 (79), 05-09 (79) — by astronomy; check the weather when the night is within four days.

2033-04-22astronomy score per night — click a bar for that night2033-05-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-04-22 Fri	48	—	unknown	02:15–04:50 (good, 2.58 h)	71.1° 07:15	6.87	45%	37.1°
2033-04-23 Sat	55	—	unknown	02:10–04:45 (good, 2.58 h)	71.1° 07:15	6.81	34%	39.7°
2033-04-24 Sun	64	—	unknown	02:10–04:45 (good, 2.58 h)	71.1° 07:10	6.75	24%	46.1°
2033-04-25 Mon	68	—	unknown	02:05–04:40 (good, 2.58 h)	71.1° 07:05	6.69	14%	55.1°
2033-04-26 Tue	70	—	unknown	02:00–04:40 (good, 2.67 h)	71.1° 07:00	6.64	7%	65.8°
2033-04-27 Wed	72	—	unknown	01:55–04:40 (good, 2.75 h)	71.1° 06:55	6.58	2%	77.3°
2033-04-28 Thu	72	—	unknown	01:50–04:35 (good, 2.75 h)	71.1° 06:55	6.52	0%	89.2°
2033-04-29 Fri	73	—	unknown	01:50–04:35 (good, 2.75 h)	71.1° 06:50	6.46	1%	100.9°
2033-04-30 Sat	75	—	unknown	01:45–04:35 (good, 2.83 h)	71.1° 06:45	6.4	5%	112.1°
2033-05-01 Sun	75	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 06:40	6.35	11%	122.4°
2033-05-02 Mon	76	—	unknown	01:35–04:30 (good, 2.92 h)	71.1° 06:40	6.29	18%	131.3°
2033-05-03 Tue	77	—	unknown	01:35–04:25 (good, 2.83 h)	71.1° 06:35	6.23	27%	138.1°
2033-05-04 Wed	78	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:30	6.17	37%	142.1°
2033-05-05 Thu	80	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:25	6.12	46%	142.6°
2033-05-06 Fri	79	—	unknown	01:25–04:20 (good, 2.92 h)	71.1° 06:20	6.06	56%	139.9°
2033-05-07 Sat	79	—	unknown	01:25–04:20 (good, 2.92 h)	71.1° 06:20	6.0	66%	134.6°
2033-05-08 Sun	80	—	unknown	01:20–04:20 (good, 3.0 h)	71.1° 06:15	5.95	74%	127.5°
2033-05-09 Mon	79	—	unknown	01:20–04:15 (good, 2.92 h)	71.1° 06:10	5.89	82%	119.4°
2033-05-10 Tue	67	—	unknown	01:20–04:15 (good, 2.92 h)	71.1° 06:05	5.83	89%	110.6°
2033-05-11 Wed	60	—	unknown	01:25–04:15 (good, 2.83 h)	71.1° 06:00	5.78	94%	101.3°
2033-05-12 Thu	52	—	unknown	01:40–04:10 (good, 2.5 h)	71.1° 06:00	5.72	98%	91.7°
2033-05-13 Fri	45	—	unknown	02:25–04:10 (good, 1.75 h)	71.1° 05:55	5.67	100%	81.9°
2033-05-14 Sat	38	—	unknown	03:10–04:10 (good, 1.0 h)	71.1° 05:50	5.62	100%	72.2°
2033-05-15 Sun	32	—	unknown	04:00–04:05 (good, 0.08 h)	71.1° 05:45	5.56	98%	62.6°
2033-05-16 Mon	30	—	unknown	00:25–04:05 (marginal, 3.67 h)	71.1° 05:45	5.51	94%	53.6°
2033-05-17 Tue	30	—	unknown	00:20–04:05 (marginal, 3.75 h)	71.1° 05:40	5.46	87%	45.7°
2033-05-18 Wed	34	—	unknown	00:05–04:00 (marginal, 3.92 h)	71.1° 05:35	5.41	80%	39.9°
2033-05-19 Thu	52	—	unknown	01:35–04:00 (good, 2.42 h)	71.1° 05:30	5.35	70%	37.3°
2033-05-20 Fri	66	—	unknown	00:25–04:00 (good, 3.58 h)	71.1° 05:25	5.3	60%	38.8°
2033-05-21 Sat	78	—	unknown	00:20–04:00 (good, 3.67 h)	71.1° 05:25	5.26	48%	44.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-04-22&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.