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: 05-04 (78), 05-03 (77), 05-02 (76), 05-01 (73), 04-30 (69) — by astronomy; check the weather when the night is within four days.

2046-04-05astronomy score per night — click a bar for that night2046-05-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-04-05 Thu	50	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:25	7.85	0%	66.1°
2046-04-06 Fri	51	—	unknown	03:20–05:20 (good, 2.0 h)	71.1° 08:20	7.8	0%	74.5°
2046-04-07 Sat	51	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:15	7.74	2%	83.4°
2046-04-08 Sun	52	—	unknown	03:10–05:15 (good, 2.08 h)	71.1° 08:15	7.68	6%	92.5°
2046-04-09 Mon	54	—	unknown	03:10–05:15 (good, 2.08 h)	71.1° 08:10	7.63	11%	101.7°
2046-04-10 Tue	54	—	unknown	03:05–05:10 (good, 2.08 h)	71.1° 08:05	7.57	18%	110.7°
2046-04-11 Wed	55	—	unknown	03:00–05:10 (good, 2.17 h)	71.1° 08:00	7.51	27%	119.4°
2046-04-12 Thu	57	—	unknown	02:55–05:10 (good, 2.25 h)	71.1° 08:00	7.46	37%	127.2°
2046-04-13 Fri	56	—	unknown	02:55–05:05 (good, 2.17 h)	71.1° 07:55	7.4	48%	133.5°
2046-04-14 Sat	57	—	unknown	02:55–05:05 (good, 2.17 h)	71.1° 07:50	7.34	59%	137.3°
2046-04-15 Sun	57	—	unknown	02:50–05:00 (good, 2.17 h)	71.1° 07:45	7.28	70%	137.5°
2046-04-16 Mon	56	—	unknown	02:50–05:00 (good, 2.17 h)	71.1° 07:40	7.23	80%	134.0°
2046-04-17 Tue	57	—	unknown	02:45–05:00 (good, 2.25 h)	71.1° 07:40	7.17	88%	127.3°
2046-04-18 Wed	51	—	unknown	02:45–04:55 (good, 2.17 h)	71.1° 07:35	7.11	95%	118.3°
2046-04-19 Thu	45	—	unknown	02:45–04:55 (good, 2.17 h)	71.1° 07:30	7.05	99%	108.1°
2046-04-20 Fri	40	—	unknown	02:50–04:50 (good, 2.0 h)	71.1° 07:25	6.99	100%	97.4°
2046-04-21 Sat	36	—	unknown	03:10–04:50 (good, 1.67 h)	71.1° 07:20	6.94	98%	86.5°
2046-04-22 Sun	33	—	unknown	03:35–04:50 (good, 1.25 h)	71.1° 07:20	6.88	94%	76.1°
2046-04-23 Mon	31	—	unknown	03:40–04:45 (good, 1.08 h)	71.1° 07:15	6.82	87%	66.3°
2046-04-24 Tue	32	—	unknown	03:30–04:45 (good, 1.25 h)	71.1° 07:10	6.76	79%	57.6°
2046-04-25 Wed	34	—	unknown	02:35–04:40 (good, 2.08 h)	71.1° 07:05	6.7	70%	50.4°
2046-04-26 Thu	43	—	unknown	02:00–04:40 (good, 2.67 h)	71.1° 07:05	6.64	60%	45.1°
2046-04-27 Fri	53	—	unknown	01:55–04:40 (good, 2.75 h)	71.1° 07:00	6.59	50%	42.4°
2046-04-28 Sat	59	—	unknown	01:55–04:35 (good, 2.67 h)	71.1° 06:55	6.53	41%	42.4°
2046-04-29 Sun	64	—	unknown	01:50–04:35 (good, 2.75 h)	71.1° 06:50	6.47	32%	45.0°
2046-04-30 Mon	69	—	unknown	01:45–04:35 (good, 2.83 h)	71.1° 06:45	6.41	23%	49.8°
2046-05-01 Tue	73	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 06:45	6.35	16%	56.2°
2046-05-02 Wed	76	—	unknown	01:40–04:30 (good, 2.83 h)	71.1° 06:40	6.3	10%	63.7°
2046-05-03 Thu	77	—	unknown	01:35–04:25 (good, 2.83 h)	71.1° 06:35	6.24	5%	72.0°
2046-05-04 Fri	78	—	unknown	01:30–04:25 (good, 2.92 h)	71.1° 06:30	6.18	2%	80.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-04-05&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.