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: 08-24 (100), 08-25 (100), 08-26 (100), 08-27 (100), 08-28 (100) — by astronomy; check the weather when the night is within four days.

2043-08-17astronomy score per night — click a bar for that night2043-09-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-08-17 Mon	98	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.75	92%	72.9°
2043-08-18 Tue	90	—	unknown	22:05–04:50 (good, 6.75 h)	87.2° 00:35	6.81	97%	67.6°
2043-08-19 Wed	64	—	unknown	02:30–04:45 (good, 2.25 h)	87.2° 00:30	6.87	99%	63.3°
2043-08-20 Thu	64	—	unknown	22:00–22:55 (good, 0.92 h)	87.2° 00:25	6.92	100%	60.3°
2043-08-21 Fri	66	—	unknown	21:55–23:10 (good, 1.25 h)	87.2° 00:20	6.98	98%	59.0°
2043-08-22 Sat	69	—	unknown	21:55–23:50 (good, 1.92 h)	87.2° 00:15	7.04	94%	59.7°
2043-08-23 Sun	74	—	unknown	21:55–01:10 (good, 3.25 h)	87.2° 00:15	7.1	87%	62.3°
2043-08-24 Mon	100	—	unknown	21:50–03:20 (good, 5.5 h)	87.2° 00:10	7.15	78%	66.6°
2043-08-25 Tue	100	—	unknown	21:50–04:35 (good, 6.75 h)	87.2° 00:05	7.21	68%	72.3°
2043-08-26 Wed	100	—	unknown	21:50–05:05 (good, 7.25 h)	87.2° 00:00	7.27	57%	78.8°
2043-08-27 Thu	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.32	46%	85.9°
2043-08-28 Fri	100	—	unknown	21:45–05:05 (good, 7.33 h)	87.2° 23:55	7.38	34%	93.2°
2043-08-29 Sat	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:50	7.44	24%	100.3°
2043-08-30 Sun	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:45	7.49	15%	106.9°
2043-08-31 Mon	100	—	unknown	21:40–05:10 (good, 7.5 h)	87.2° 23:40	7.55	8%	112.5°
2043-09-01 Tue	100	—	unknown	21:35–05:10 (good, 7.58 h)	87.2° 23:40	7.6	3%	117.0°
2043-09-02 Wed	100	—	unknown	21:35–05:15 (good, 7.67 h)	87.2° 23:35	7.66	0%	119.9°
2043-09-03 Thu	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:30	7.72	0%	121.0°
2043-09-04 Fri	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:25	7.77	2%	120.4°
2043-09-05 Sat	100	—	unknown	21:30–05:15 (good, 7.75 h)	87.2° 23:20	7.83	6%	118.2°
2043-09-06 Sun	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:20	7.88	11%	114.6°
2043-09-07 Mon	100	—	unknown	21:25–05:20 (good, 7.92 h)	87.2° 23:15	7.94	18%	110.1°
2043-09-08 Tue	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:10	7.99	26%	104.9°
2043-09-09 Wed	100	—	unknown	21:20–05:20 (good, 8.0 h)	87.2° 23:05	8.05	35%	99.2°
2043-09-10 Thu	100	—	unknown	21:20–05:25 (good, 8.08 h)	87.2° 23:00	8.1	44%	93.2°
2043-09-11 Fri	100	—	unknown	21:15–05:20 (good, 8.08 h)	87.2° 23:00	8.15	54%	87.1°
2043-09-12 Sat	100	—	unknown	21:15–05:15 (good, 8.0 h)	87.2° 22:55	8.21	63%	81.0°
2043-09-13 Sun	100	—	unknown	21:10–05:10 (good, 8.0 h)	87.2° 22:50	8.26	72%	75.1°
2043-09-14 Mon	94	—	unknown	21:10–05:05 (good, 7.92 h)	87.2° 22:45	8.31	81%	69.6°
2043-09-15 Tue	86	—	unknown	21:10–05:05 (good, 7.92 h)	87.2° 22:45	8.37	88%	64.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-08-17&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.