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: 06-21 (100), 06-22 (100), 06-23 (100), 06-24 (100), 06-25 (100) — by astronomy; check the weather when the night is within four days.

2036-06-21astronomy score per night — click a bar for that night2036-07-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-06-21 Sat	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:20	4.42	7%	89.7°
2036-06-22 Sun	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:15	4.43	2%	97.1°
2036-06-23 Mon	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:10	4.43	0%	104.3°
2036-06-24 Tue	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:05	4.44	1%	110.8°
2036-06-25 Wed	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.45	5%	116.0°
2036-06-26 Thu	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 04:00	4.46	11%	119.5°
2036-06-27 Fri	100	—	unknown	23:15–03:40 (good, 4.42 h)	87.2° 03:55	4.48	20%	120.9°
2036-06-28 Sat	100	—	unknown	23:10–03:40 (good, 4.5 h)	87.2° 03:50	4.49	30%	120.1°
2036-06-29 Sun	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:45	4.51	41%	117.3°
2036-06-30 Mon	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.53	52%	113.0°
2036-07-01 Tue	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:40	4.55	63%	107.6°
2036-07-02 Wed	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:35	4.57	72%	101.6°
2036-07-03 Thu	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:30	4.6	81%	95.2°
2036-07-04 Fri	100	—	unknown	23:10–03:45 (good, 4.58 h)	87.2° 03:25	4.63	88%	88.8°
2036-07-05 Sat	78	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:25	4.65	94%	82.5°
2036-07-06 Sun	70	—	unknown	23:10–03:50 (good, 4.67 h)	87.2° 03:20	4.69	98%	76.6°
2036-07-07 Mon	62	—	unknown	23:35–03:50 (good, 4.25 h)	87.2° 03:15	4.72	100%	71.2°
2036-07-08 Tue	55	—	unknown	23:50–03:50 (good, 4.0 h)	87.2° 03:10	4.75	100%	66.5°
2036-07-09 Wed	54	—	unknown	23:05–01:05 (good, 2.0 h)	87.2° 03:05	4.79	98%	62.8°
2036-07-10 Thu	57	—	unknown	23:05–01:35 (good, 2.5 h)	87.2° 03:05	4.82	95%	60.4°
2036-07-11 Fri	64	—	unknown	23:05–02:35 (good, 3.5 h)	87.2° 03:00	4.86	90%	59.2°
2036-07-12 Sat	94	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 02:55	4.9	83%	59.5°
2036-07-13 Sun	98	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:50	4.94	75%	61.3°
2036-07-14 Mon	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	4.98	66%	64.4°
2036-07-15 Tue	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.02	57%	68.7°
2036-07-16 Wed	100	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.07	47%	74.0°
2036-07-17 Thu	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:35	5.11	36%	80.2°
2036-07-18 Fri	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.16	26%	87.0°
2036-07-19 Sat	100	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.2	17%	94.1°
2036-07-20 Sun	100	—	unknown	22:55–04:10 (good, 5.25 h)	87.2° 02:25	5.25	9%	101.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-06-21&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.