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 North America Nebula: 05-20 (100), 05-21 (100), 05-22 (100), 05-23 (100), 05-24 (100) — by astronomy; check the weather when the night is within four days.

2036-05-02astronomy score per night — click a bar for that night2036-05-31

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-05-02 Fri	82	—	unknown	01:25–04:30 (good, 3.08 h)	87.2° 07:35	6.27	46%	118.7°
2036-05-03 Sat	81	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:30	6.21	58%	121.0°
2036-05-04 Sun	81	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:25	6.16	69%	121.2°
2036-05-05 Mon	81	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:25	6.1	78%	119.4°
2036-05-06 Tue	71	—	unknown	01:20–04:20 (good, 3.0 h)	87.2° 07:20	6.04	87%	115.9°
2036-05-07 Wed	66	—	unknown	01:20–04:20 (good, 3.0 h)	87.2° 07:15	5.99	93%	110.9°
2036-05-08 Thu	61	—	unknown	01:20–04:20 (good, 3.0 h)	87.2° 07:10	5.93	98%	105.0°
2036-05-09 Fri	55	—	unknown	01:25–04:15 (good, 2.83 h)	87.2° 07:05	5.87	100%	98.6°
2036-05-10 Sat	51	—	unknown	01:45–04:15 (good, 2.5 h)	87.2° 07:05	5.82	99%	92.0°
2036-05-11 Sun	48	—	unknown	02:05–04:15 (good, 2.17 h)	87.2° 07:00	5.76	97%	85.4°
2036-05-12 Mon	46	—	unknown	02:05–04:10 (good, 2.08 h)	87.2° 06:55	5.71	93%	79.1°
2036-05-13 Tue	47	—	unknown	01:40–04:10 (good, 2.5 h)	87.2° 06:50	5.65	87%	73.3°
2036-05-14 Wed	50	—	unknown	01:05–04:10 (good, 3.08 h)	87.2° 06:45	5.6	80%	68.2°
2036-05-15 Thu	62	—	unknown	00:30–04:05 (good, 3.58 h)	87.2° 06:45	5.55	72%	64.0°
2036-05-16 Fri	71	—	unknown	00:25–04:05 (good, 3.67 h)	87.2° 06:40	5.49	63%	60.9°
2036-05-17 Sat	81	—	unknown	00:20–04:05 (good, 3.75 h)	87.2° 06:35	5.44	54%	59.2°
2036-05-18 Sun	88	—	unknown	00:15–04:00 (good, 3.75 h)	87.2° 06:30	5.39	45%	58.8°
2036-05-19 Mon	96	—	unknown	00:10–04:00 (good, 3.83 h)	87.2° 06:30	5.34	35%	60.0°
2036-05-20 Tue	100	—	unknown	00:10–04:00 (good, 3.83 h)	87.2° 06:25	5.29	26%	62.7°
2036-05-21 Wed	100	—	unknown	00:05–03:55 (good, 3.83 h)	87.2° 06:20	5.24	18%	66.8°
2036-05-22 Thu	100	—	unknown	00:00–03:55 (good, 3.92 h)	87.2° 06:15	5.19	10%	72.1°
2036-05-23 Fri	100	—	unknown	23:55–03:55 (good, 4.0 h)	87.2° 06:10	5.15	5%	78.4°
2036-05-24 Sat	100	—	unknown	23:55–03:55 (good, 4.0 h)	87.2° 06:10	5.1	1%	85.4°
2036-05-25 Sun	100	—	unknown	23:50–03:50 (good, 4.0 h)	87.2° 06:05	5.06	0%	92.7°
2036-05-26 Mon	100	—	unknown	23:45–03:50 (good, 4.08 h)	87.2° 06:00	5.01	2%	100.1°
2036-05-27 Tue	100	—	unknown	23:40–03:50 (good, 4.17 h)	87.2° 05:55	4.97	6%	107.0°
2036-05-28 Wed	100	—	unknown	23:35–03:50 (good, 4.25 h)	87.2° 05:50	4.93	13%	113.0°
2036-05-29 Thu	100	—	unknown	23:35–03:50 (good, 4.25 h)	87.2° 05:50	4.89	22%	117.6°
2036-05-30 Fri	100	—	unknown	23:35–03:45 (good, 4.17 h)	87.2° 05:45	4.85	33%	120.4°
2036-05-31 Sat	100	—	unknown	23:30–03:45 (good, 4.25 h)	87.2° 05:40	4.81	44%	121.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-05-02&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.