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 Triangulum Pinwheel: 07-19 (65), 07-18 (63), 07-17 (57), 07-16 (52), 07-15 (45) — by astronomy; check the weather when the night is within four days.

2039-06-20astronomy score per night — click a bar for that night2039-07-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2039-06-20 Mon	12	—	unknown	03:30–03:40 (good, 0.17 h)	79.2° 09:00	4.42	1%	50.5°
2039-06-21 Tue	13	—	unknown	03:30–03:40 (good, 0.17 h)	79.2° 08:55	4.42	0%	61.0°
2039-06-22 Wed	15	—	unknown	03:25–03:40 (good, 0.25 h)	79.2° 08:50	4.42	1%	71.8°
2039-06-23 Thu	16	—	unknown	03:20–03:40 (good, 0.33 h)	79.2° 08:50	4.43	4%	82.9°
2039-06-24 Fri	17	—	unknown	03:15–03:40 (good, 0.42 h)	79.2° 08:45	4.43	10%	94.1°
2039-06-25 Sat	19	—	unknown	03:15–03:40 (good, 0.42 h)	79.2° 08:40	4.44	16%	105.5°
2039-06-26 Sun	22	—	unknown	03:10–03:40 (good, 0.5 h)	79.2° 08:35	4.45	24%	117.0°
2039-06-27 Mon	23	—	unknown	03:05–03:40 (good, 0.58 h)	79.2° 08:30	4.47	34%	128.3°
2039-06-28 Tue	25	—	unknown	03:00–03:40 (good, 0.67 h)	79.2° 08:30	4.48	44%	139.4°
2039-06-29 Wed	25	—	unknown	02:55–03:40 (good, 0.75 h)	79.2° 08:25	4.5	55%	149.2°
2039-06-30 Thu	28	—	unknown	02:55–03:45 (good, 0.83 h)	79.2° 08:20	4.51	66%	155.8°
2039-07-01 Fri	29	—	unknown	02:50–03:45 (good, 0.92 h)	79.2° 08:15	4.53	77%	155.6°
2039-07-02 Sat	30	—	unknown	02:50–03:45 (good, 0.92 h)	79.2° 08:15	4.56	86%	148.3°
2039-07-03 Sun	27	—	unknown	02:50–03:45 (good, 0.92 h)	79.2° 08:10	4.58	93%	137.2°
2039-07-04 Mon	28	—	unknown	02:45–03:45 (good, 1.0 h)	79.2° 08:05	4.61	98%	124.4°
2039-07-05 Tue	26	—	unknown	02:50–03:45 (good, 0.92 h)	79.2° 08:00	4.63	100%	110.9°
2039-07-06 Wed	23	—	unknown	02:55–03:50 (good, 0.92 h)	79.2° 07:55	4.66	99%	97.3°
2039-07-07 Thu	20	—	unknown	03:30–03:50 (good, 0.33 h)	79.2° 07:55	4.69	95%	83.9°
2039-07-08 Fri	18	—	unknown	02:00–03:50 (marginal, 1.83 h)	79.2° 07:50	4.73	89%	71.0°
2039-07-09 Sat	17	—	unknown	01:55–03:50 (marginal, 1.92 h)	79.2° 07:45	4.76	81%	58.6°
2039-07-10 Sun	18	—	unknown	01:50–03:55 (marginal, 2.08 h)	79.2° 07:40	4.79	72%	47.1°
2039-07-11 Mon	20	—	unknown	01:45–03:55 (marginal, 2.17 h)	79.2° 07:35	4.83	62%	36.7°
2039-07-12 Tue	24	—	unknown	03:05–03:55 (good, 0.83 h)	79.2° 07:35	4.87	52%	28.4°
2039-07-13 Wed	30	—	unknown	02:25–03:55 (good, 1.5 h)	79.2° 07:30	4.91	42%	23.7°
2039-07-14 Thu	37	—	unknown	02:10–04:00 (good, 1.83 h)	79.2° 07:25	4.95	33%	24.4°
2039-07-15 Fri	45	—	unknown	01:55–04:00 (good, 2.08 h)	79.2° 07:20	4.99	24%	29.9°
2039-07-16 Sat	52	—	unknown	01:50–04:00 (good, 2.17 h)	79.2° 07:20	5.03	17%	38.2°
2039-07-17 Sun	57	—	unknown	01:45–04:00 (good, 2.25 h)	79.2° 07:15	5.08	10%	47.8°
2039-07-18 Mon	63	—	unknown	01:40–04:05 (good, 2.42 h)	79.2° 07:10	5.12	5%	58.2°
2039-07-19 Tue	65	—	unknown	01:40–04:05 (good, 2.42 h)	79.2° 07:05	5.17	2%	68.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2039-06-20&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.