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: 07-15 (54), 07-14 (53), 07-13 (51), 07-12 (50), 07-11 (48) — by astronomy; check the weather when the night is within four days.

2027-06-22astronomy score per night — click a bar for that night2027-07-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-06-22 Tue	7	—	unknown	03:00–03:40 (marginal, 0.67 h)	79.1° 08:50	4.42	87%	79.9°
2027-06-23 Wed	8	—	unknown	02:55–03:40 (marginal, 0.75 h)	79.1° 08:50	4.43	80%	68.4°
2027-06-24 Thu	8	—	unknown	02:55–03:40 (marginal, 0.75 h)	79.1° 08:45	4.43	72%	56.9°
2027-06-25 Fri	9	—	unknown	02:50–03:40 (marginal, 0.83 h)	79.1° 08:40	4.44	62%	45.5°
2027-06-26 Sat	11	—	unknown	02:40–03:40 (marginal, 1.0 h)	79.1° 08:35	4.45	53%	34.2°
2027-06-27 Sun	13	—	unknown	03:30–03:40 (good, 0.17 h)	79.1° 08:30	4.46	43%	23.4°
2027-06-28 Mon	17	—	unknown	03:20–03:40 (good, 0.33 h)	79.1° 08:30	4.48	32%	15.3°
2027-06-29 Tue	20	—	unknown	03:05–03:40 (good, 0.58 h)	79.1° 08:25	4.49	23%	16.1°
2027-06-30 Wed	25	—	unknown	03:00–03:45 (good, 0.75 h)	79.1° 08:20	4.51	14%	25.5°
2027-07-01 Thu	29	—	unknown	02:50–03:45 (good, 0.92 h)	79.1° 08:15	4.53	7%	38.1°
2027-07-02 Fri	31	—	unknown	02:45–03:45 (good, 1.0 h)	79.1° 08:10	4.55	2%	51.9°
2027-07-03 Sat	32	—	unknown	02:40–03:45 (good, 1.08 h)	79.1° 08:10	4.58	0%	66.3°
2027-07-04 Sun	34	—	unknown	02:35–03:45 (good, 1.17 h)	79.1° 08:05	4.6	1%	80.9°
2027-07-05 Mon	35	—	unknown	02:35–03:45 (good, 1.17 h)	79.1° 08:00	4.63	5%	95.6°
2027-07-06 Tue	38	—	unknown	02:30–03:50 (good, 1.33 h)	79.1° 07:55	4.66	11%	110.1°
2027-07-07 Wed	40	—	unknown	02:25–03:50 (good, 1.42 h)	79.1° 07:55	4.69	20%	124.2°
2027-07-08 Thu	41	—	unknown	02:20–03:50 (good, 1.5 h)	79.1° 07:50	4.72	30%	137.7°
2027-07-09 Fri	43	—	unknown	02:20–03:50 (good, 1.5 h)	79.1° 07:45	4.76	41%	150.2°
2027-07-10 Sat	46	—	unknown	02:15–03:55 (good, 1.67 h)	79.1° 07:40	4.79	52%	160.9°
2027-07-11 Sun	48	—	unknown	02:10–03:55 (good, 1.75 h)	79.1° 07:35	4.83	62%	165.8°
2027-07-12 Mon	50	—	unknown	02:05–03:55 (good, 1.83 h)	79.1° 07:35	4.87	72%	161.0°
2027-07-13 Tue	51	—	unknown	02:00–03:55 (good, 1.92 h)	79.1° 07:30	4.9	80%	151.2°
2027-07-14 Wed	53	—	unknown	02:05–04:00 (good, 1.92 h)	79.1° 07:25	4.95	88%	140.1°
2027-07-15 Thu	54	—	unknown	02:00–04:00 (good, 2.0 h)	79.1° 07:20	4.99	93%	128.7°
2027-07-16 Fri	48	—	unknown	02:00–04:00 (good, 2.0 h)	79.1° 07:15	5.03	97%	117.3°
2027-07-17 Sat	43	—	unknown	02:05–04:00 (good, 1.92 h)	79.1° 07:15	5.07	100%	105.8°
2027-07-18 Sun	37	—	unknown	02:10–04:05 (good, 1.92 h)	79.1° 07:10	5.12	100%	94.3°
2027-07-19 Mon	31	—	unknown	03:05–04:05 (good, 1.0 h)	79.1° 07:05	5.17	98%	82.8°
2027-07-20 Tue	27	—	unknown	01:15–04:05 (marginal, 2.83 h)	79.1° 07:00	5.21	95%	71.3°
2027-07-21 Wed	23	—	unknown	01:15–04:10 (marginal, 2.92 h)	79.1° 07:00	5.26	91%	59.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-06-22&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.