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: 08-02 (100), 08-03 (100), 08-04 (100), 08-05 (100), 08-06 (100) — by astronomy; check the weather when the night is within four days.

2027-07-29astronomy score per night — click a bar for that night2027-08-27

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-07-29 Thu	80	—	unknown	01:00–04:20 (good, 3.33 h)	79.1° 06:25	5.67	17%	46.0°
2027-07-30 Fri	89	—	unknown	00:55–04:20 (good, 3.42 h)	79.1° 06:20	5.72	9%	59.9°
2027-07-31 Sat	96	—	unknown	00:50–04:25 (good, 3.58 h)	79.1° 06:20	5.78	3%	74.4°
2027-08-01 Sun	98	—	unknown	00:45–04:25 (good, 3.67 h)	79.1° 06:15	5.83	0%	89.1°
2027-08-02 Mon	100	—	unknown	00:45–04:25 (good, 3.67 h)	79.1° 06:10	5.89	0%	103.8°
2027-08-03 Tue	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.1° 06:05	5.94	4%	118.4°
2027-08-04 Wed	100	—	unknown	00:35–04:30 (good, 3.92 h)	79.1° 06:05	6.0	9%	132.6°
2027-08-05 Thu	100	—	unknown	00:30–04:30 (good, 4.0 h)	79.1° 06:00	6.06	17%	146.0°
2027-08-06 Fri	100	—	unknown	00:30–04:35 (good, 4.08 h)	79.1° 05:55	6.11	26%	157.9°
2027-08-07 Sat	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.1° 05:50	6.17	37%	165.4°
2027-08-08 Sun	100	—	unknown	00:20–04:35 (good, 4.25 h)	79.1° 05:45	6.23	47%	163.1°
2027-08-09 Mon	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.1° 05:45	6.28	57%	153.9°
2027-08-10 Tue	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.1° 05:40	6.34	67%	142.9°
2027-08-11 Wed	100	—	unknown	00:15–04:40 (good, 4.42 h)	79.1° 05:35	6.4	76%	131.6°
2027-08-12 Thu	100	—	unknown	00:10–04:40 (good, 4.5 h)	79.1° 05:30	6.46	84%	120.1°
2027-08-13 Fri	100	—	unknown	00:15–04:45 (good, 4.5 h)	79.1° 05:25	6.51	90%	108.7°
2027-08-14 Sat	100	—	unknown	00:20–04:45 (good, 4.42 h)	79.1° 05:25	6.57	95%	97.2°
2027-08-15 Sun	74	—	unknown	01:00–04:45 (good, 3.75 h)	79.1° 05:20	6.63	98%	85.7°
2027-08-16 Mon	59	—	unknown	02:20–04:50 (good, 2.5 h)	79.1° 05:15	6.69	100%	74.2°
2027-08-17 Tue	45	—	unknown	23:35–04:50 (marginal, 5.25 h)	79.1° 05:10	6.74	100%	62.7°
2027-08-18 Wed	33	—	unknown	23:35–04:50 (marginal, 5.25 h)	79.1° 05:10	6.8	98%	51.3°
2027-08-19 Thu	25	—	unknown	23:35–04:55 (marginal, 5.33 h)	79.1° 05:05	6.86	94%	39.9°
2027-08-20 Fri	22	—	unknown	23:30–04:55 (marginal, 5.42 h)	79.1° 05:00	6.92	88%	28.9°
2027-08-21 Sat	28	—	unknown	23:15–04:55 (marginal, 5.67 h)	79.1° 04:55	6.97	81%	19.1°
2027-08-22 Sun	38	—	unknown	23:05–05:00 (marginal, 5.92 h)	79.1° 04:50	7.03	72%	14.2°
2027-08-23 Mon	52	—	unknown	22:50–05:00 (marginal, 6.17 h)	79.1° 04:50	7.09	62%	18.9°
2027-08-24 Tue	68	—	unknown	23:40–05:00 (good, 5.33 h)	79.1° 04:45	7.15	52%	29.3°
2027-08-25 Wed	83	—	unknown	23:15–05:00 (good, 5.75 h)	79.1° 04:40	7.2	41%	41.5°
2027-08-26 Thu	91	—	unknown	23:10–05:05 (good, 5.92 h)	79.1° 04:35	7.26	30%	54.7°
2027-08-27 Fri	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.1° 04:30	7.32	20%	68.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-07-29&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.