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: 07-12 (41), 07-11 (33), 06-30 (27), 07-10 (27), 06-29 (26) — by astronomy; check the weather when the night is within four days.

2042-06-13astronomy score per night — click a bar for that night2042-07-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-06-13 Fri	4	—	unknown	04:05–04:30 (marginal, 0.42 h)	79.2° 09:25	4.48	19%	18.9°
2042-06-14 Sat	6	—	unknown	04:00–04:30 (marginal, 0.5 h)	79.2° 09:25	4.46	11%	21.4°
2042-06-15 Sun	7	—	unknown	03:50–04:30 (marginal, 0.67 h)	79.2° 09:20	4.45	5%	30.9°
2042-06-16 Mon	7	—	unknown	03:45–04:30 (marginal, 0.75 h)	79.2° 09:15	4.44	1%	42.9°
2042-06-17 Tue	8	—	unknown	03:45–04:30 (marginal, 0.75 h)	79.2° 09:10	4.43	0%	55.6°
2042-06-18 Wed	10	—	unknown	03:10–04:30 (marginal, 1.33 h)	79.2° 09:05	4.43	2%	68.3°
2042-06-19 Thu	11	—	unknown	03:35–03:40 (good, 0.08 h)	79.2° 09:05	4.42	6%	80.9°
2042-06-20 Fri	12	—	unknown	03:30–03:40 (good, 0.17 h)	79.2° 09:00	4.42	11%	93.2°
2042-06-21 Sat	13	—	unknown	03:30–03:40 (good, 0.17 h)	79.2° 08:55	4.42	18%	105.2°
2042-06-22 Sun	15	—	unknown	03:25–03:40 (good, 0.25 h)	79.2° 08:50	4.42	26%	116.9°
2042-06-23 Mon	17	—	unknown	03:20–03:40 (good, 0.33 h)	79.2° 08:45	4.43	36%	128.1°
2042-06-24 Tue	18	—	unknown	03:15–03:40 (good, 0.42 h)	79.2° 08:45	4.44	45%	138.8°
2042-06-25 Wed	20	—	unknown	03:10–03:40 (good, 0.5 h)	79.2° 08:40	4.44	54%	148.8°
2042-06-26 Thu	22	—	unknown	03:10–03:40 (good, 0.5 h)	79.2° 08:35	4.46	64%	157.1°
2042-06-27 Fri	23	—	unknown	03:05–03:40 (good, 0.58 h)	79.2° 08:30	4.47	72%	161.4°
2042-06-28 Sat	25	—	unknown	03:00–03:40 (good, 0.67 h)	79.2° 08:30	4.48	81%	158.9°
2042-06-29 Sun	26	—	unknown	03:00–03:40 (good, 0.67 h)	79.2° 08:25	4.5	88%	151.1°
2042-06-30 Mon	27	—	unknown	03:00–03:45 (good, 0.75 h)	79.2° 08:20	4.52	94%	140.8°
2042-07-01 Tue	25	—	unknown	02:55–03:45 (good, 0.83 h)	79.2° 08:15	4.54	98%	129.3°
2042-07-02 Wed	25	—	unknown	02:55–03:45 (good, 0.83 h)	79.2° 08:10	4.56	100%	117.2°
2042-07-03 Thu	22	—	unknown	03:00–03:45 (good, 0.75 h)	79.2° 08:10	4.59	99%	104.5°
2042-07-04 Fri	19	—	unknown	03:05–03:45 (good, 0.67 h)	79.2° 08:05	4.61	97%	91.5°
2042-07-05 Sat	18	—	unknown	02:05–03:50 (marginal, 1.75 h)	79.2° 08:00	4.64	92%	78.3°
2042-07-06 Sun	16	—	unknown	02:05–03:50 (marginal, 1.75 h)	79.2° 07:55	4.67	84%	65.1°
2042-07-07 Mon	16	—	unknown	02:00–03:50 (marginal, 1.83 h)	79.2° 07:50	4.7	75%	51.9°
2042-07-08 Tue	17	—	unknown	01:55–03:50 (marginal, 1.92 h)	79.2° 07:50	4.73	65%	39.2°
2042-07-09 Wed	20	—	unknown	01:50–03:50 (marginal, 2.0 h)	79.2° 07:45	4.77	54%	27.7°
2042-07-10 Thu	27	—	unknown	02:35–03:55 (good, 1.33 h)	79.2° 07:40	4.8	42%	19.6°
2042-07-11 Fri	33	—	unknown	02:25–03:55 (good, 1.5 h)	79.2° 07:35	4.84	31%	19.7°
2042-07-12 Sat	41	—	unknown	02:05–03:55 (good, 1.83 h)	79.2° 07:30	4.88	21%	27.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-06-13&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.