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: 07-23 (73), 07-22 (72), 07-21 (71), 07-20 (68), 07-19 (66) — by astronomy; check the weather when the night is within four days.

2037-07-04astronomy score per night — click a bar for that night2037-08-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-07-04 Sat	17	—	unknown	02:05–03:45 (marginal, 1.67 h)	79.1° 08:05	4.62	57%	36.7°
2037-07-05 Sun	20	—	unknown	03:00–03:50 (good, 0.83 h)	79.2° 08:00	4.65	47%	29.2°
2037-07-06 Mon	25	—	unknown	02:45–03:50 (good, 1.08 h)	79.2° 07:55	4.68	38%	24.9°
2037-07-07 Tue	31	—	unknown	02:35–03:50 (good, 1.25 h)	79.2° 07:50	4.71	28%	25.9°
2037-07-08 Wed	37	—	unknown	02:20–03:50 (good, 1.5 h)	79.2° 07:45	4.74	20%	31.9°
2037-07-09 Thu	42	—	unknown	02:15–03:50 (good, 1.58 h)	79.2° 07:45	4.78	12%	41.0°
2037-07-10 Fri	46	—	unknown	02:10–03:55 (good, 1.75 h)	79.2° 07:40	4.81	6%	51.9°
2037-07-11 Sat	48	—	unknown	02:10–03:55 (good, 1.75 h)	79.2° 07:35	4.85	2%	63.9°
2037-07-12 Sun	50	—	unknown	02:05–03:55 (good, 1.83 h)	79.2° 07:30	4.89	0%	76.6°
2037-07-13 Mon	52	—	unknown	02:00–03:55 (good, 1.92 h)	79.1° 07:25	4.93	1%	89.6°
2037-07-14 Tue	55	—	unknown	01:55–04:00 (good, 2.08 h)	79.2° 07:25	4.97	5%	102.9°
2037-07-15 Wed	57	—	unknown	01:50–04:00 (good, 2.17 h)	79.2° 07:20	5.01	11%	116.0°
2037-07-16 Thu	59	—	unknown	01:50–04:00 (good, 2.17 h)	79.2° 07:15	5.06	19%	128.7°
2037-07-17 Fri	62	—	unknown	01:45–04:05 (good, 2.33 h)	79.2° 07:10	5.1	29%	140.4°
2037-07-18 Sat	65	—	unknown	01:40–04:05 (good, 2.42 h)	79.1° 07:10	5.15	40%	150.0°
2037-07-19 Sun	66	—	unknown	01:35–04:05 (good, 2.5 h)	79.2° 07:05	5.19	52%	155.1°
2037-07-20 Mon	68	—	unknown	01:35–04:05 (good, 2.5 h)	79.2° 07:00	5.24	63%	153.5°
2037-07-21 Tue	71	—	unknown	01:35–04:10 (good, 2.58 h)	79.2° 06:55	5.29	73%	146.3°
2037-07-22 Wed	72	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:50	5.34	82%	136.5°
2037-07-23 Thu	73	—	unknown	01:30–04:10 (good, 2.67 h)	79.2° 06:50	5.39	90%	125.7°
2037-07-24 Fri	65	—	unknown	01:30–04:15 (good, 2.75 h)	79.2° 06:45	5.44	95%	114.4°
2037-07-25 Sat	57	—	unknown	01:35–04:15 (good, 2.67 h)	79.2° 06:40	5.49	98%	103.0°
2037-07-26 Sun	49	—	unknown	01:50–04:15 (good, 2.42 h)	79.2° 06:35	5.54	100%	91.7°
2037-07-27 Mon	42	—	unknown	02:45–04:20 (good, 1.58 h)	79.1° 06:30	5.6	99%	80.5°
2037-07-28 Tue	35	—	unknown	03:50–04:20 (good, 0.5 h)	79.2° 06:30	5.65	97%	69.6°
2037-07-29 Wed	30	—	unknown	00:40–04:20 (marginal, 3.67 h)	79.2° 06:25	5.7	93%	59.0°
2037-07-30 Thu	27	—	unknown	00:35–04:25 (marginal, 3.83 h)	79.2° 06:20	5.76	87%	48.8°
2037-07-31 Fri	27	—	unknown	00:30–04:25 (marginal, 3.92 h)	79.2° 06:15	5.81	80%	39.4°
2037-08-01 Sat	29	—	unknown	00:25–04:25 (marginal, 4.0 h)	79.1° 06:15	5.87	72%	31.3°
2037-08-02 Sun	37	—	unknown	00:15–04:30 (marginal, 4.25 h)	79.2° 06:10	5.92	63%	25.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-07-04&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.