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: 01-29 (97), 01-28 (96), 01-30 (96), 01-27 (95), 01-31 (93) — by astronomy; check the weather when the night is within four days.

2043-01-19astronomy score per night — click a bar for that night2043-02-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-01-19 Mon	30	—	unknown	19:00–23:45 (marginal, 4.75 h)	79.2° 18:00	11.14	67%	23.2°
2043-01-20 Tue	22	—	unknown	19:00–23:25 (marginal, 4.42 h)	79.2° 18:00	11.11	78%	34.0°
2043-01-21 Wed	23	—	unknown	19:00–23:15 (marginal, 4.25 h)	79.2° 17:55	11.09	86%	46.5°
2043-01-22 Thu	28	—	unknown	19:05–23:15 (marginal, 4.17 h)	79.2° 17:50	11.06	93%	59.5°
2043-01-23 Fri	38	—	unknown	19:05–19:20 (good, 0.25 h)	79.2° 17:45	11.03	98%	72.7°
2043-01-24 Sat	51	—	unknown	19:05–21:05 (good, 2.0 h)	79.2° 17:40	11.0	100%	85.8°
2043-01-25 Sun	65	—	unknown	19:05–22:20 (good, 3.25 h)	79.2° 17:40	10.98	99%	98.6°
2043-01-26 Mon	80	—	unknown	19:05–22:50 (good, 3.75 h)	79.2° 17:35	10.95	97%	111.1°
2043-01-27 Tue	95	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:30	10.92	92%	123.3°
2043-01-28 Wed	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:25	10.89	86%	134.8°
2043-01-29 Thu	97	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:20	10.86	79%	145.7°
2043-01-30 Fri	96	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:20	10.83	70%	155.2°
2043-01-31 Sat	93	—	unknown	19:15–22:45 (good, 3.5 h)	79.2° 17:15	10.79	62%	161.6°
2043-02-01 Sun	91	—	unknown	19:15–22:45 (good, 3.5 h)	79.2° 17:10	10.76	52%	161.8°
2043-02-02 Mon	89	—	unknown	19:15–22:40 (good, 3.42 h)	79.2° 17:05	10.73	43%	155.5°
2043-02-03 Tue	88	—	unknown	19:15–22:35 (good, 3.33 h)	79.2° 17:05	10.69	34%	146.2°
2043-02-04 Wed	86	—	unknown	19:15–22:30 (good, 3.25 h)	79.2° 17:00	10.66	25%	135.5°
2043-02-05 Thu	82	—	unknown	19:20–22:25 (good, 3.08 h)	79.2° 16:55	10.63	17%	124.1°
2043-02-06 Fri	80	—	unknown	19:20–22:25 (good, 3.08 h)	79.2° 16:50	10.59	10%	112.1°
2043-02-07 Sat	78	—	unknown	19:20–22:20 (good, 3.0 h)	79.2° 16:45	10.55	5%	99.7°
2043-02-08 Sun	76	—	unknown	19:20–22:15 (good, 2.92 h)	79.2° 16:45	10.52	1%	86.9°
2043-02-09 Mon	72	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:40	10.48	0%	73.8°
2043-02-10 Tue	70	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:35	10.44	2%	60.6°
2043-02-11 Wed	65	—	unknown	19:25–22:05 (good, 2.67 h)	79.2° 16:30	10.41	5%	47.4°
2043-02-12 Thu	60	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:25	10.37	12%	34.6°
2043-02-13 Fri	49	—	unknown	19:30–21:50 (good, 2.33 h)	79.2° 16:25	10.33	20%	23.5°
2043-02-14 Sat	39	—	unknown	19:30–21:35 (good, 2.08 h)	79.2° 16:20	10.29	30%	17.3°
2043-02-15 Sun	29	—	unknown	19:30–21:05 (good, 1.58 h)	79.2° 16:15	10.25	41%	21.1°
2043-02-16 Mon	21	—	unknown	19:30–22:05 (marginal, 2.58 h)	79.2° 16:10	10.21	53%	31.2°
2043-02-17 Tue	17	—	unknown	19:30–21:55 (marginal, 2.42 h)	79.2° 16:10	10.17	64%	43.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-01-19&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.