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), 05-04 (78), 05-03 (77), 05-02 (76), 04-30 (75) — by astronomy; check the weather when the night is within four days.

2033-04-06astronomy score per night — click a bar for that night2033-05-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-04-06 Wed	52	—	unknown	03:20–05:20 (good, 2.0 h)	71.1° 08:20	7.79	53%	139.9°
2033-04-07 Thu	50	—	unknown	03:20–05:15 (good, 1.92 h)	71.1° 08:15	7.73	63%	142.7°
2033-04-08 Fri	51	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:10	7.68	72%	142.2°
2033-04-09 Sat	52	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:10	7.62	80%	138.6°
2033-04-10 Sun	50	—	unknown	03:10–05:10 (good, 2.0 h)	71.1° 08:05	7.56	87%	132.7°
2033-04-11 Mon	47	—	unknown	03:10–05:10 (good, 2.0 h)	71.1° 08:00	7.51	93%	125.3°
2033-04-12 Tue	44	—	unknown	03:05–05:05 (good, 2.0 h)	71.1° 07:55	7.45	97%	116.9°
2033-04-13 Wed	40	—	unknown	03:10–05:05 (good, 1.92 h)	71.1° 07:50	7.39	99%	108.0°
2033-04-14 Thu	36	—	unknown	03:15–05:05 (good, 1.83 h)	71.1° 07:50	7.33	100%	98.6°
2033-04-15 Fri	32	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 07:45	7.28	99%	89.0°
2033-04-16 Sat	28	—	unknown	04:15–05:00 (good, 0.75 h)	71.1° 07:40	7.22	96%	79.3°
2033-04-17 Sun	26	—	unknown	04:40–05:00 (good, 0.33 h)	71.1° 07:35	7.16	91%	69.6°
2033-04-18 Mon	25	—	unknown	02:10–05:35 (marginal, 3.42 h)	71.1° 07:35	7.1	84%	60.3°
2033-04-19 Tue	26	—	unknown	04:50–04:55 (good, 0.08 h)	71.1° 07:30	7.04	76%	51.6°
2033-04-20 Wed	29	—	unknown	03:50–04:50 (good, 1.0 h)	71.1° 07:25	6.99	67%	44.1°
2033-04-21 Thu	35	—	unknown	02:45–04:50 (good, 2.08 h)	71.1° 07:20	6.93	56%	38.9°
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°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-04-06&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.