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: 10-19 (100), 10-20 (100), 10-21 (100), 10-22 (100), 10-23 (100) — by astronomy; check the weather when the night is within four days.

2038-10-15astronomy score per night — click a bar for that night2038-11-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-10-15 Fri	48	—	unknown	19:50–02:20 (marginal, 6.5 h)	79.2° 01:20	9.82	93%	29.5°
2038-10-16 Sat	83	—	unknown	20:15–20:45 (good, 0.5 h)	79.2° 01:15	9.87	88%	37.5°
2038-10-17 Sun	87	—	unknown	20:10–23:50 (good, 3.67 h)	79.2° 01:10	9.91	81%	47.0°
2038-10-18 Mon	93	—	unknown	20:10–03:05 (good, 6.92 h)	79.2° 01:05	9.95	73%	57.3°
2038-10-19 Tue	100	—	unknown	20:10–05:00 (good, 8.83 h)	79.2° 01:05	10.0	64%	68.2°
2038-10-20 Wed	100	—	unknown	20:05–06:05 (good, 10.0 h)	79.2° 01:00	10.04	54%	79.4°
2038-10-21 Thu	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:55	10.08	44%	91.1°
2038-10-22 Fri	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.2° 00:50	10.12	34%	103.1°
2038-10-23 Sat	100	—	unknown	20:05–06:15 (good, 10.17 h)	79.2° 00:45	10.16	24%	115.4°
2038-10-24 Sun	100	—	unknown	20:00–06:15 (good, 10.25 h)	79.2° 00:45	10.2	15%	127.8°
2038-10-25 Mon	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:40	10.24	8%	139.9°
2038-10-26 Tue	100	—	unknown	20:00–06:10 (good, 10.17 h)	79.2° 00:35	10.28	3%	150.3°
2038-10-27 Wed	100	—	unknown	20:00–06:05 (good, 10.08 h)	79.2° 00:30	10.32	0%	156.0°
2038-10-28 Thu	100	—	unknown	19:55–06:00 (good, 10.08 h)	79.2° 00:30	10.36	1%	153.5°
2038-10-29 Fri	100	—	unknown	19:55–05:55 (good, 10.0 h)	79.2° 00:25	10.39	5%	144.5°
2038-10-30 Sat	100	—	unknown	19:55–04:50 (good, 9.92 h)	79.2° 00:20	10.43	11%	132.7°
2038-10-31 Sun	100	—	unknown	18:55–04:50 (good, 9.92 h)	79.2° 23:15	10.47	20%	120.1°
2038-11-01 Mon	100	—	unknown	18:50–04:45 (good, 9.92 h)	79.2° 23:10	10.5	29%	107.4°
2038-11-02 Tue	100	—	unknown	18:50–04:40 (good, 9.83 h)	79.2° 23:10	10.54	40%	95.0°
2038-11-03 Wed	100	—	unknown	18:50–04:35 (good, 9.75 h)	79.2° 23:05	10.58	50%	82.9°
2038-11-04 Thu	100	—	unknown	18:50–04:35 (good, 9.75 h)	79.2° 23:00	10.61	60%	71.2°
2038-11-05 Fri	100	—	unknown	19:00–04:30 (good, 9.5 h)	79.2° 22:55	10.65	70%	60.0°
2038-11-06 Sat	92	—	unknown	22:40–04:25 (good, 5.75 h)	79.2° 22:50	10.68	79%	49.3°
2038-11-07 Sun	84	—	unknown	03:20–04:20 (good, 1.0 h)	79.2° 22:50	10.71	86%	39.5°
2038-11-08 Mon	60	—	unknown	18:45–04:45 (marginal, 10.0 h)	79.2° 22:45	10.75	92%	31.0°
2038-11-09 Tue	36	—	unknown	18:45–04:20 (marginal, 9.58 h)	79.2° 22:40	10.78	96%	25.2°
2038-11-10 Wed	33	—	unknown	18:45–21:45 (marginal, 3.0 h)	79.2° 22:35	10.81	99%	23.9°
2038-11-11 Thu	33	—	unknown	18:45–21:50 (marginal, 3.08 h)	79.2° 22:35	10.84	100%	27.9°
2038-11-12 Fri	42	—	unknown	18:40–23:20 (marginal, 4.67 h)	79.2° 22:30	10.87	99%	35.3°
2038-11-13 Sat	57	—	unknown	18:40–03:20 (marginal, 8.67 h)	79.2° 22:25	10.9	96%	44.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-10-15&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.