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: 06-30 (100), 07-01 (100), 07-02 (100), 07-03 (100), 07-04 (100) — by astronomy; check the weather when the night is within four days.

2044-06-30astronomy score per night — click a bar for that night2044-07-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-06-30 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:45	4.53	37%	122.0°
2044-07-01 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:40	4.55	47%	114.1°
2044-07-02 Sat	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.58	57%	105.7°
2044-07-03 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:35	4.6	67%	97.0°
2044-07-04 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	71.1° 02:30	4.63	76%	88.4°
2044-07-05 Tue	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:25	4.66	84%	79.9°
2044-07-06 Wed	100	—	unknown	23:10–03:50 (good, 4.67 h)	71.1° 02:20	4.69	90%	71.7°
2044-07-07 Thu	100	—	unknown	23:25–03:50 (good, 4.42 h)	71.1° 02:15	4.72	95%	64.1°
2044-07-08 Fri	60	—	unknown	00:20–03:50 (good, 3.5 h)	71.1° 02:15	4.75	98%	57.1°
2044-07-09 Sat	51	—	unknown	03:35–03:55 (good, 0.33 h)	71.1° 02:10	4.79	100%	51.3°
2044-07-10 Sun	44	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:05	4.82	100%	47.1°
2044-07-11 Mon	45	—	unknown	23:05–03:55 (marginal, 4.83 h)	71.1° 02:00	4.86	97%	45.0°
2044-07-12 Tue	50	—	unknown	23:05–23:30 (good, 0.42 h)	71.1° 02:00	4.9	94%	45.3°
2044-07-13 Wed	59	—	unknown	23:00–01:05 (good, 2.08 h)	71.1° 01:55	4.94	88%	48.2°
2044-07-14 Thu	95	—	unknown	23:00–02:50 (good, 3.83 h)	71.1° 01:50	4.98	81%	53.1°
2044-07-15 Fri	97	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:45	5.03	72%	59.8°
2044-07-16 Sat	100	—	unknown	23:00–04:00 (good, 5.0 h)	71.1° 01:40	5.07	62%	67.7°
2044-07-17 Sun	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:40	5.11	52%	76.6°
2044-07-18 Mon	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:35	5.16	41%	86.1°
2044-07-19 Tue	100	—	unknown	22:55–04:05 (good, 5.17 h)	71.1° 01:30	5.21	30%	96.0°
2044-07-20 Wed	100	—	unknown	22:55–04:10 (good, 5.25 h)	71.1° 01:25	5.26	20%	106.0°
2044-07-21 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.3	12%	115.6°
2044-07-22 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:20	5.35	5%	124.2°
2044-07-23 Sat	100	—	unknown	22:50–04:10 (good, 5.33 h)	71.1° 01:15	5.4	1%	131.0°
2044-07-24 Sun	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:10	5.45	0%	134.7°
2044-07-25 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.51	2%	134.7°
2044-07-26 Tue	100	—	unknown	22:45–04:15 (good, 5.5 h)	71.1° 01:05	5.56	7%	131.0°
2044-07-27 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 01:00	5.61	14%	124.8°
2044-07-28 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:55	5.67	22%	117.1°
2044-07-29 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	71.1° 00:50	5.72	32%	108.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-06-30&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.