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: 02-03 (84), 02-04 (84), 02-02 (83), 02-05 (81), 02-06 (78) — by astronomy; check the weather when the night is within four days.

2037-01-26astronomy score per night — click a bar for that night2037-02-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-01-26 Mon	26	—	unknown	19:10–23:10 (marginal, 4.0 h)	79.1° 17:30	10.93	73%	39.5°
2037-01-27 Tue	25	—	unknown	19:10–23:00 (marginal, 3.83 h)	79.1° 17:30	10.9	82%	50.4°
2037-01-28 Wed	28	—	unknown	19:10–23:00 (marginal, 3.83 h)	79.2° 17:25	10.87	90%	62.7°
2037-01-29 Thu	36	—	unknown	19:10–19:50 (good, 0.67 h)	79.2° 17:20	10.84	96%	75.7°
2037-01-30 Fri	47	—	unknown	19:10–21:05 (good, 1.92 h)	79.2° 17:15	10.81	99%	89.3°
2037-01-31 Sat	60	—	unknown	19:15–22:15 (good, 3.0 h)	79.1° 17:10	10.78	100%	103.1°
2037-02-01 Sun	73	—	unknown	19:15–22:25 (good, 3.17 h)	79.2° 17:10	10.75	97%	116.7°
2037-02-02 Mon	83	—	unknown	19:15–22:25 (good, 3.17 h)	79.2° 17:05	10.71	92%	129.8°
2037-02-03 Tue	84	—	unknown	19:15–22:25 (good, 3.17 h)	79.2° 17:00	10.68	84%	141.6°
2037-02-04 Wed	84	—	unknown	19:20–22:30 (good, 3.17 h)	79.2° 16:55	10.64	74%	150.9°
2037-02-05 Thu	81	—	unknown	19:20–22:25 (good, 3.08 h)	79.1° 16:55	10.61	64%	155.3°
2037-02-06 Fri	78	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:50	10.57	53%	152.9°
2037-02-07 Sat	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:45	10.54	43%	145.5°
2037-02-08 Sun	74	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:40	10.5	33%	135.9°
2037-02-09 Mon	71	—	unknown	19:25–22:10 (good, 2.75 h)	79.1° 16:35	10.46	24%	125.4°
2037-02-10 Tue	69	—	unknown	19:25–22:05 (good, 2.67 h)	79.1° 16:35	10.43	16%	114.6°
2037-02-11 Wed	66	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:30	10.39	9%	103.7°
2037-02-12 Thu	64	—	unknown	19:25–21:55 (good, 2.5 h)	79.2° 16:25	10.35	4%	92.8°
2037-02-13 Fri	61	—	unknown	19:30–21:55 (good, 2.42 h)	79.2° 16:20	10.31	1%	81.9°
2037-02-14 Sat	59	—	unknown	19:30–21:50 (good, 2.33 h)	79.1° 16:15	10.27	0%	71.2°
2037-02-15 Sun	57	—	unknown	19:30–21:45 (good, 2.25 h)	79.2° 16:15	10.23	0%	60.7°
2037-02-16 Mon	55	—	unknown	19:30–21:40 (good, 2.17 h)	79.2° 16:10	10.19	3%	50.5°
2037-02-17 Tue	50	—	unknown	19:35–21:40 (good, 2.08 h)	79.2° 16:05	10.15	7%	40.9°
2037-02-18 Wed	46	—	unknown	19:35–21:35 (good, 2.0 h)	79.2° 16:00	10.11	12%	32.5°
2037-02-19 Thu	39	—	unknown	19:35–21:20 (good, 1.75 h)	79.1° 16:00	10.07	19%	26.4°
2037-02-20 Fri	32	—	unknown	19:35–21:10 (good, 1.58 h)	79.2° 15:55	10.03	27%	24.7°
2037-02-21 Sat	25	—	unknown	19:35–21:00 (good, 1.42 h)	79.2° 15:50	9.98	36%	28.4°
2037-02-22 Sun	20	—	unknown	19:40–19:45 (good, 0.08 h)	79.2° 15:45	9.94	46%	36.2°
2037-02-23 Mon	16	—	unknown	19:40–21:35 (marginal, 1.92 h)	79.2° 15:40	9.9	57%	46.2°
2037-02-24 Tue	14	—	unknown	19:40–21:25 (marginal, 1.75 h)	79.1° 15:40	9.86	68%	57.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-01-26&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.