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.

2038-07-31astronomy score per night — click a bar for that night2038-08-29

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-07-31 Sat	96	—	unknown	00:50–04:25 (good, 3.58 h)	79.2° 06:20	5.8	0%	93.4°
2038-08-01 Sun	98	—	unknown	00:45–04:25 (good, 3.67 h)	79.2° 06:15	5.85	1%	105.9°
2038-08-02 Mon	100	—	unknown	00:40–04:25 (good, 3.75 h)	79.2° 06:10	5.91	5%	118.4°
2038-08-03 Tue	100	—	unknown	00:40–04:30 (good, 3.83 h)	79.2° 06:05	5.96	11%	130.6°
2038-08-04 Wed	100	—	unknown	00:35–04:30 (good, 3.92 h)	79.2° 06:00	6.02	19%	142.1°
2038-08-05 Thu	100	—	unknown	00:30–04:30 (good, 4.0 h)	79.2° 06:00	6.08	29%	151.4°
2038-08-06 Fri	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:55	6.13	40%	155.8°
2038-08-07 Sat	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:50	6.19	51%	153.0°
2038-08-08 Sun	100	—	unknown	00:25–04:35 (good, 4.17 h)	79.2° 05:45	6.25	62%	144.7°
2038-08-09 Mon	100	—	unknown	00:20–04:40 (good, 4.33 h)	79.2° 05:40	6.3	73%	133.9°
2038-08-10 Tue	100	—	unknown	00:20–04:40 (good, 4.33 h)	79.2° 05:40	6.36	82%	122.0°
2038-08-11 Wed	100	—	unknown	00:20–04:40 (good, 4.33 h)	79.2° 05:35	6.42	90%	109.9°
2038-08-12 Thu	100	—	unknown	00:25–04:45 (good, 4.33 h)	79.2° 05:30	6.47	95%	97.6°
2038-08-13 Fri	72	—	unknown	01:05–04:45 (good, 3.67 h)	79.2° 05:25	6.53	99%	85.5°
2038-08-14 Sat	57	—	unknown	02:20–04:45 (good, 2.42 h)	79.2° 05:25	6.59	100%	73.6°
2038-08-15 Sun	45	—	unknown	23:35–04:50 (marginal, 5.25 h)	79.2° 05:20	6.65	99%	62.1°
2038-08-16 Mon	35	—	unknown	23:35–04:50 (marginal, 5.25 h)	79.2° 05:15	6.7	96%	51.1°
2038-08-17 Tue	29	—	unknown	23:30–04:50 (marginal, 5.33 h)	79.2° 05:10	6.76	91%	41.0°
2038-08-18 Wed	29	—	unknown	23:25–04:50 (marginal, 5.42 h)	79.2° 05:05	6.82	85%	32.2°
2038-08-19 Thu	36	—	unknown	23:15–04:55 (marginal, 5.67 h)	79.2° 05:05	6.88	77%	26.0°
2038-08-20 Fri	46	—	unknown	23:05–04:55 (marginal, 5.83 h)	79.2° 05:00	6.94	69%	24.1°
2038-08-21 Sat	67	—	unknown	23:55–03:35 (good, 3.67 h)	79.2° 04:55	6.99	60%	27.4°
2038-08-22 Sun	82	—	unknown	23:25–05:00 (good, 5.58 h)	79.2° 04:50	7.05	50%	34.4°
2038-08-23 Mon	87	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.11	41%	43.5°
2038-08-24 Tue	92	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:45	7.16	31%	53.7°
2038-08-25 Wed	98	—	unknown	23:10–05:00 (good, 5.83 h)	79.2° 04:40	7.22	22%	64.8°
2038-08-26 Thu	100	—	unknown	23:10–05:05 (good, 5.92 h)	79.2° 04:35	7.28	14%	76.4°
2038-08-27 Fri	100	—	unknown	23:05–05:05 (good, 6.0 h)	79.2° 04:30	7.33	8%	88.5°
2038-08-28 Sat	100	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:30	7.39	3%	101.0°
2038-08-29 Sun	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:25	7.45	0%	113.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-07-31&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.