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: 07-08 (100), 07-09 (100), 07-10 (100), 07-11 (100), 07-12 (100) — by astronomy; check the weather when the night is within four days.

2038-07-08astronomy score per night — click a bar for that night2038-08-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2038-07-08 Thu	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:15	4.73	42%	113.3°
2038-07-09 Fri	100	—	unknown	23:05–03:50 (good, 4.75 h)	87.2° 03:10	4.77	53%	108.8°
2038-07-10 Sat	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:05	4.8	64%	103.2°
2038-07-11 Sun	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 03:00	4.84	75%	96.8°
2038-07-12 Mon	100	—	unknown	23:05–03:55 (good, 4.83 h)	87.2° 02:55	4.88	84%	90.1°
2038-07-13 Tue	100	—	unknown	23:00–03:55 (good, 4.92 h)	87.2° 02:55	4.92	92%	83.5°
2038-07-14 Wed	75	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:50	4.96	97%	77.2°
2038-07-15 Thu	68	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:45	5.0	100%	71.6°
2038-07-16 Fri	61	—	unknown	23:00–04:00 (good, 5.0 h)	87.2° 02:40	5.05	100%	67.1°
2038-07-17 Sat	62	—	unknown	22:55–02:30 (good, 3.58 h)	87.2° 02:40	5.09	98%	63.9°
2038-07-18 Sun	67	—	unknown	22:55–02:45 (good, 3.83 h)	87.2° 02:35	5.14	93%	62.2°
2038-07-19 Mon	95	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:30	5.18	87%	62.0°
2038-07-20 Tue	99	—	unknown	22:55–04:05 (good, 5.17 h)	87.2° 02:25	5.23	80%	63.3°
2038-07-21 Wed	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.28	71%	65.8°
2038-07-22 Thu	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:20	5.33	62%	69.3°
2038-07-23 Fri	100	—	unknown	22:50–04:10 (good, 5.33 h)	87.2° 02:15	5.38	53%	73.6°
2038-07-24 Sat	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:10	5.43	43%	78.6°
2038-07-25 Sun	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:05	5.48	34%	83.9°
2038-07-26 Mon	100	—	unknown	22:45–04:15 (good, 5.5 h)	87.2° 02:00	5.53	25%	89.6°
2038-07-27 Tue	100	—	unknown	22:45–04:20 (good, 5.58 h)	87.2° 02:00	5.58	17%	95.3°
2038-07-28 Wed	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:55	5.64	10%	101.0°
2038-07-29 Thu	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:50	5.69	5%	106.3°
2038-07-30 Fri	100	—	unknown	22:40–04:20 (good, 5.67 h)	87.2° 01:45	5.74	1%	111.1°
2038-07-31 Sat	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:45	5.8	0%	114.9°
2038-08-01 Sun	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:40	5.85	1%	117.4°
2038-08-02 Mon	100	—	unknown	22:35–04:25 (good, 5.83 h)	87.2° 01:35	5.91	5%	118.1°
2038-08-03 Tue	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:30	5.96	11%	117.1°
2038-08-04 Wed	100	—	unknown	22:30–04:30 (good, 6.0 h)	87.2° 01:25	6.02	19%	114.3°
2038-08-05 Thu	100	—	unknown	22:25–04:30 (good, 6.08 h)	87.2° 01:25	6.08	29%	110.0°
2038-08-06 Fri	100	—	unknown	22:25–04:35 (good, 6.17 h)	87.2° 01:20	6.13	40%	104.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2038-07-08&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.