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: 08-18 (100), 08-19 (100), 08-20 (100), 08-21 (100), 08-22 (100) — by astronomy; check the weather when the night is within four days.

2036-07-26astronomy score per night — click a bar for that night2036-08-24

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-07-26 Sat	85	—	unknown	01:10–04:15 (good, 3.08 h)	79.2° 06:35	5.56	17%	135.0°
2036-07-27 Sun	89	—	unknown	01:05–04:20 (good, 3.25 h)	79.1° 06:30	5.61	27%	145.7°
2036-07-28 Mon	91	—	unknown	01:00–04:20 (good, 3.33 h)	79.1° 06:25	5.66	37%	153.3°
2036-07-29 Tue	93	—	unknown	00:55–04:20 (good, 3.42 h)	79.1° 06:25	5.72	48%	155.4°
2036-07-30 Wed	94	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:20	5.77	58%	151.3°
2036-07-31 Thu	96	—	unknown	00:55–04:25 (good, 3.5 h)	79.2° 06:15	5.82	68%	143.4°
2036-08-01 Fri	97	—	unknown	00:50–04:25 (good, 3.58 h)	79.1° 06:10	5.88	77%	133.8°
2036-08-02 Sat	98	—	unknown	00:50–04:30 (good, 3.67 h)	79.1° 06:10	5.94	85%	123.5°
2036-08-03 Sun	95	—	unknown	00:50–04:30 (good, 3.67 h)	79.2° 06:05	5.99	91%	112.9°
2036-08-04 Mon	77	—	unknown	00:55–04:30 (good, 3.58 h)	79.2° 06:00	6.05	96%	102.2°
2036-08-05 Tue	66	—	unknown	01:10–04:35 (good, 3.42 h)	79.2° 05:55	6.1	99%	91.4°
2036-08-06 Wed	54	—	unknown	02:10–04:35 (good, 2.42 h)	79.1° 05:50	6.16	100%	80.6°
2036-08-07 Thu	44	—	unknown	03:20–04:35 (good, 1.25 h)	79.1° 05:50	6.22	99%	69.9°
2036-08-08 Fri	36	—	unknown	00:05–04:40 (marginal, 4.58 h)	79.2° 05:45	6.27	97%	59.4°
2036-08-09 Sat	30	—	unknown	00:00–04:40 (marginal, 4.67 h)	79.2° 05:40	6.33	93%	49.1°
2036-08-10 Sun	27	—	unknown	23:55–04:40 (marginal, 4.75 h)	79.2° 05:35	6.39	87%	39.5°
2036-08-11 Mon	28	—	unknown	23:50–04:40 (marginal, 4.83 h)	79.1° 05:30	6.45	80%	31.1°
2036-08-12 Tue	37	—	unknown	23:35–04:45 (marginal, 5.17 h)	79.1° 05:30	6.5	71%	25.5°
2036-08-13 Wed	49	—	unknown	02:05–03:25 (good, 1.33 h)	79.2° 05:25	6.56	62%	25.1°
2036-08-14 Thu	76	—	unknown	23:55–04:45 (good, 4.83 h)	79.2° 05:20	6.62	51%	30.3°
2036-08-15 Fri	85	—	unknown	23:50–04:50 (good, 5.0 h)	79.1° 05:15	6.68	41%	39.3°
2036-08-16 Sat	92	—	unknown	23:45–04:50 (good, 5.08 h)	79.1° 05:15	6.73	30%	50.4°
2036-08-17 Sun	98	—	unknown	23:40–04:50 (good, 5.17 h)	79.2° 05:10	6.79	20%	62.7°
2036-08-18 Mon	100	—	unknown	23:40–04:55 (good, 5.25 h)	79.2° 05:05	6.85	11%	75.8°
2036-08-19 Tue	100	—	unknown	23:35–04:55 (good, 5.33 h)	79.2° 05:00	6.91	5%	89.3°
2036-08-20 Wed	100	—	unknown	23:30–04:55 (good, 5.42 h)	79.1° 04:55	6.96	1%	103.1°
2036-08-21 Thu	100	—	unknown	23:25–04:55 (good, 5.5 h)	79.1° 04:55	7.02	0%	116.7°
2036-08-22 Fri	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:50	7.08	2%	129.8°
2036-08-23 Sat	100	—	unknown	23:20–05:00 (good, 5.67 h)	79.2° 04:45	7.13	7%	141.6°
2036-08-24 Sun	100	—	unknown	23:15–05:00 (good, 5.75 h)	79.2° 04:40	7.19	14%	151.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-07-26&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.