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: 05-11 (85), 05-13 (85), 05-10 (84), 05-12 (84), 05-08 (83) — by astronomy; check the weather when the night is within four days.

2038-04-14astronomy score per night — click a bar for that night2038-05-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-04-14 Wed	56	—	unknown	02:55–05:05 (good, 2.17 h)	71.1° 07:50	7.35	73%	133.0°
2038-04-15 Thu	51	—	unknown	02:55–05:00 (good, 2.08 h)	71.1° 07:45	7.29	82%	127.4°
2038-04-16 Fri	49	—	unknown	02:50–05:00 (good, 2.17 h)	71.1° 07:40	7.23	90%	119.3°
2038-04-17 Sat	44	—	unknown	02:55–05:00 (good, 2.08 h)	71.1° 07:40	7.17	96%	109.7°
2038-04-18 Sun	38	—	unknown	03:00–04:55 (good, 1.92 h)	71.1° 07:35	7.11	99%	99.1°
2038-04-19 Mon	33	—	unknown	03:40–04:55 (good, 1.25 h)	71.1° 07:30	7.06	100%	88.2°
2038-04-20 Tue	29	—	unknown	04:15–04:50 (good, 0.58 h)	71.1° 07:25	7.0	96%	77.5°
2038-04-21 Wed	27	—	unknown	04:35–04:50 (good, 0.25 h)	71.1° 07:20	6.94	91%	67.3°
2038-04-22 Thu	28	—	unknown	04:30–04:50 (good, 0.33 h)	71.1° 07:20	6.88	83%	58.4°
2038-04-23 Fri	30	—	unknown	03:45–04:45 (good, 1.0 h)	71.1° 07:15	6.82	74%	51.2°
2038-04-24 Sat	37	—	unknown	02:35–04:45 (good, 2.17 h)	71.1° 07:10	6.77	64%	46.3°
2038-04-25 Sun	49	—	unknown	02:05–04:40 (good, 2.58 h)	71.1° 07:05	6.71	53%	44.3°
2038-04-26 Mon	58	—	unknown	02:00–04:40 (good, 2.67 h)	71.1° 07:00	6.65	43%	45.1°
2038-04-27 Tue	66	—	unknown	01:55–04:40 (good, 2.75 h)	71.1° 07:00	6.59	34%	48.6°
2038-04-28 Wed	70	—	unknown	01:55–04:35 (good, 2.67 h)	71.1° 06:55	6.53	25%	53.9°
2038-04-29 Thu	73	—	unknown	01:50–04:35 (good, 2.75 h)	71.1° 06:50	6.47	17%	60.6°
2038-04-30 Fri	74	—	unknown	01:45–04:35 (good, 2.83 h)	71.1° 06:45	6.42	11%	68.1°
2038-05-01 Sat	74	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 06:45	6.36	6%	76.1°
2038-05-02 Sun	76	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 06:40	6.3	2%	84.4°
2038-05-03 Mon	77	—	unknown	01:35–04:25 (good, 2.83 h)	71.1° 06:35	6.24	0%	92.9°
2038-05-04 Tue	78	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:30	6.19	0%	101.3°
2038-05-05 Wed	79	—	unknown	01:25–04:25 (good, 3.0 h)	71.1° 06:25	6.13	2%	109.6°
2038-05-06 Thu	80	—	unknown	01:20–04:20 (good, 3.0 h)	71.1° 06:25	6.07	6%	117.4°
2038-05-07 Fri	81	—	unknown	01:20–04:20 (good, 3.0 h)	71.1° 06:20	6.01	11%	124.5°
2038-05-08 Sat	83	—	unknown	01:15–04:20 (good, 3.08 h)	71.1° 06:15	5.96	18%	130.4°
2038-05-09 Sun	83	—	unknown	01:10–04:15 (good, 3.08 h)	71.1° 06:10	5.9	27%	134.3°
2038-05-10 Mon	84	—	unknown	01:10–04:15 (good, 3.08 h)	71.1° 06:05	5.85	37%	135.7°
2038-05-11 Tue	85	—	unknown	01:05–04:15 (good, 3.17 h)	71.1° 06:05	5.79	47%	134.0°
2038-05-12 Wed	84	—	unknown	01:05–04:10 (good, 3.08 h)	71.1° 06:00	5.73	58%	129.3°
2038-05-13 Thu	85	—	unknown	01:00–04:10 (good, 3.17 h)	71.1° 05:55	5.68	69%	122.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-04-14&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.