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: 05-10 (90), 05-11 (90), 05-08 (89), 05-09 (89), 05-12 (89) — by astronomy; check the weather when the night is within four days.

2030-04-13astronomy score per night — click a bar for that night2030-05-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-04-13 Sat	60	—	unknown	02:45–05:05 (good, 2.33 h)	87.2° 08:50	7.41	77%	126.5°
2030-04-14 Sun	60	—	unknown	02:45–05:05 (good, 2.33 h)	87.2° 08:45	7.35	86%	127.6°
2030-04-15 Mon	54	—	unknown	02:40–05:00 (good, 2.33 h)	87.2° 08:45	7.29	93%	126.1°
2030-04-16 Tue	53	—	unknown	02:40–05:00 (good, 2.33 h)	87.2° 08:40	7.23	98%	122.0°
2030-04-17 Wed	52	—	unknown	02:35–05:00 (good, 2.42 h)	87.2° 08:35	7.18	100%	115.8°
2030-04-18 Thu	47	—	unknown	02:40–04:55 (good, 2.25 h)	87.2° 08:30	7.12	99%	108.0°
2030-04-19 Fri	44	—	unknown	02:40–04:55 (good, 2.25 h)	87.2° 08:30	7.06	95%	99.2°
2030-04-20 Sat	41	—	unknown	02:40–04:50 (good, 2.17 h)	87.2° 08:25	7.0	89%	90.2°
2030-04-21 Sun	41	—	unknown	02:35–04:50 (good, 2.25 h)	87.2° 08:20	6.94	80%	81.2°
2030-04-22 Mon	42	—	unknown	02:25–04:50 (good, 2.42 h)	87.2° 08:15	6.89	70%	72.9°
2030-04-23 Tue	47	—	unknown	02:15–04:45 (good, 2.5 h)	87.2° 08:10	6.83	59%	65.5°
2030-04-24 Wed	56	—	unknown	01:55–04:45 (good, 2.83 h)	87.2° 08:10	6.77	48%	59.4°
2030-04-25 Thu	62	—	unknown	01:50–04:45 (good, 2.92 h)	87.2° 08:05	6.71	38%	55.1°
2030-04-26 Fri	68	—	unknown	01:45–04:40 (good, 2.92 h)	87.2° 08:00	6.65	28%	52.8°
2030-04-27 Sat	73	—	unknown	01:40–04:40 (good, 3.0 h)	87.2° 07:55	6.59	20%	52.6°
2030-04-28 Sun	77	—	unknown	01:35–04:35 (good, 3.0 h)	87.2° 07:50	6.54	12%	54.4°
2030-04-29 Mon	78	—	unknown	01:35–04:35 (good, 3.0 h)	87.2° 07:50	6.48	7%	58.0°
2030-04-30 Tue	80	—	unknown	01:30–04:35 (good, 3.08 h)	87.2° 07:45	6.42	3%	63.0°
2030-05-01 Wed	80	—	unknown	01:25–04:30 (good, 3.08 h)	87.2° 07:40	6.36	0%	68.9°
2030-05-02 Thu	82	—	unknown	01:20–04:30 (good, 3.17 h)	87.2° 07:35	6.3	0%	75.5°
2030-05-03 Fri	84	—	unknown	01:15–04:30 (good, 3.25 h)	87.2° 07:30	6.25	2%	82.5°
2030-05-04 Sat	84	—	unknown	01:15–04:25 (good, 3.17 h)	87.2° 07:30	6.19	5%	89.7°
2030-05-05 Sun	86	—	unknown	01:10–04:25 (good, 3.25 h)	87.2° 07:25	6.13	10%	96.9°
2030-05-06 Mon	86	—	unknown	01:05–04:20 (good, 3.25 h)	87.2° 07:20	6.07	16%	103.9°
2030-05-07 Tue	88	—	unknown	01:00–04:20 (good, 3.33 h)	87.2° 07:15	6.02	24%	110.7°
2030-05-08 Wed	89	—	unknown	01:00–04:20 (good, 3.33 h)	87.2° 07:15	5.96	32%	116.8°
2030-05-09 Thu	89	—	unknown	01:00–04:15 (good, 3.25 h)	87.2° 07:10	5.9	42%	121.9°
2030-05-10 Fri	90	—	unknown	00:55–04:15 (good, 3.33 h)	87.2° 07:05	5.85	52%	125.7°
2030-05-11 Sat	90	—	unknown	00:55–04:15 (good, 3.33 h)	87.2° 07:00	5.79	63%	127.6°
2030-05-12 Sun	89	—	unknown	00:50–04:10 (good, 3.33 h)	87.2° 06:55	5.74	73%	127.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-04-13&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.