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: 05-17 (92), 05-14 (91), 05-15 (91), 05-16 (91), 05-18 (91) — by astronomy; check the weather when the night is within four days.

2032-04-23astronomy score per night — click a bar for that night2032-05-22

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2032-04-23 Fri	50	—	unknown	02:25–04:45 (good, 2.33 h)	71.1° 07:10	6.8	97%	109.6°
2032-04-24 Sat	44	—	unknown	02:30–04:45 (good, 2.25 h)	71.1° 07:10	6.74	100%	99.6°
2032-04-25 Sun	37	—	unknown	03:00–04:40 (good, 1.67 h)	71.1° 07:05	6.68	100%	89.2°
2032-04-26 Mon	33	—	unknown	03:40–04:40 (good, 1.0 h)	71.1° 07:00	6.62	98%	78.6°
2032-04-27 Tue	29	—	unknown	04:15–04:40 (good, 0.42 h)	71.1° 06:55	6.56	94%	68.1°
2032-04-28 Wed	27	—	unknown	01:30–04:35 (marginal, 3.08 h)	71.1° 06:55	6.51	88%	58.0°
2032-04-29 Thu	29	—	unknown	01:25–04:35 (marginal, 3.17 h)	71.1° 06:50	6.45	79%	48.8°
2032-04-30 Fri	32	—	unknown	03:35–04:30 (good, 0.92 h)	71.1° 06:45	6.39	69%	41.5°
2032-05-01 Sat	41	—	unknown	02:05–04:30 (good, 2.42 h)	71.1° 06:40	6.33	58%	37.4°
2032-05-02 Sun	56	—	unknown	01:35–04:30 (good, 2.92 h)	71.1° 06:35	6.27	47%	37.6°
2032-05-03 Mon	65	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:35	6.22	36%	42.1°
2032-05-04 Tue	73	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:30	6.16	25%	49.7°
2032-05-05 Wed	79	—	unknown	01:25–04:25 (good, 3.0 h)	71.1° 06:25	6.1	16%	59.2°
2032-05-06 Thu	80	—	unknown	01:20–04:20 (good, 3.0 h)	71.1° 06:20	6.04	8%	69.7°
2032-05-07 Fri	82	—	unknown	01:15–04:20 (good, 3.08 h)	71.1° 06:15	5.99	3%	80.7°
2032-05-08 Sat	84	—	unknown	01:10–04:20 (good, 3.17 h)	71.1° 06:15	5.93	0%	91.6°
2032-05-09 Sun	85	—	unknown	01:10–04:15 (good, 3.08 h)	71.1° 06:10	5.88	0%	102.4°
2032-05-10 Mon	87	—	unknown	01:05–04:15 (good, 3.17 h)	71.1° 06:05	5.82	2%	112.6°
2032-05-11 Tue	87	—	unknown	01:00–04:15 (good, 3.25 h)	71.1° 06:00	5.76	6%	122.1°
2032-05-12 Wed	88	—	unknown	00:55–04:10 (good, 3.25 h)	71.1° 05:55	5.71	12%	130.5°
2032-05-13 Thu	90	—	unknown	00:50–04:10 (good, 3.33 h)	71.1° 05:55	5.66	19%	137.2°
2032-05-14 Fri	91	—	unknown	00:50–04:10 (good, 3.33 h)	71.1° 05:50	5.6	27%	141.6°
2032-05-15 Sat	91	—	unknown	00:45–04:05 (good, 3.33 h)	71.1° 05:45	5.55	36%	143.1°
2032-05-16 Sun	91	—	unknown	00:45–04:05 (good, 3.33 h)	71.1° 05:40	5.5	46%	141.3°
2032-05-17 Mon	92	—	unknown	00:40–04:05 (good, 3.42 h)	71.1° 05:40	5.44	55%	136.7°
2032-05-18 Tue	91	—	unknown	00:40–04:00 (good, 3.33 h)	71.1° 05:35	5.39	64%	130.1°
2032-05-19 Wed	91	—	unknown	00:35–04:00 (good, 3.42 h)	71.1° 05:30	5.34	73%	122.1°
2032-05-20 Thu	89	—	unknown	00:35–04:00 (good, 3.42 h)	71.1° 05:25	5.29	82%	113.0°
2032-05-21 Fri	73	—	unknown	00:40–03:55 (good, 3.25 h)	71.1° 05:20	5.24	89%	103.2°
2032-05-22 Sat	63	—	unknown	00:45–03:55 (good, 3.17 h)	71.1° 05:20	5.2	94%	93.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2032-04-23&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.