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: 05-16 (99), 05-15 (97), 05-14 (96), 05-13 (91), 05-12 (84) — by astronomy; check the weather when the night is within four days.

2034-04-17astronomy score per night — click a bar for that night2034-05-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-04-17 Mon	67	—	unknown	02:20–05:00 (good, 2.67 h)	87.2° 08:35	7.17	1%	65.4°
2034-04-18 Tue	68	—	unknown	02:15–04:55 (good, 2.67 h)	87.2° 08:30	7.12	0%	72.6°
2034-04-19 Wed	69	—	unknown	02:10–04:55 (good, 2.75 h)	87.2° 08:30	7.06	2%	80.7°
2034-04-20 Thu	69	—	unknown	02:10–04:50 (good, 2.67 h)	87.2° 08:25	7.0	7%	89.3°
2034-04-21 Fri	71	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:20	6.94	14%	97.7°
2034-04-22 Sat	72	—	unknown	02:00–04:50 (good, 2.83 h)	87.2° 08:15	6.88	23%	105.5°
2034-04-23 Sun	72	—	unknown	01:55–04:45 (good, 2.83 h)	87.2° 08:10	6.83	33%	112.5°
2034-04-24 Mon	73	—	unknown	01:55–04:45 (good, 2.83 h)	87.2° 08:10	6.77	44%	118.1°
2034-04-25 Tue	73	—	unknown	01:55–04:40 (good, 2.75 h)	87.2° 08:05	6.71	55%	122.2°
2034-04-26 Wed	73	—	unknown	01:50–04:40 (good, 2.83 h)	87.2° 08:00	6.65	65%	124.4°
2034-04-27 Thu	74	—	unknown	01:50–04:40 (good, 2.83 h)	87.2° 07:55	6.59	74%	124.8°
2034-04-28 Fri	72	—	unknown	01:50–04:35 (good, 2.75 h)	87.2° 07:50	6.53	82%	123.3°
2034-04-29 Sat	66	—	unknown	01:45–04:35 (good, 2.83 h)	87.2° 07:50	6.48	89%	120.2°
2034-04-30 Sun	64	—	unknown	01:45–04:35 (good, 2.83 h)	87.2° 07:45	6.42	94%	115.9°
2034-05-01 Mon	58	—	unknown	01:45–04:30 (good, 2.75 h)	87.2° 07:40	6.36	98%	110.6°
2034-05-02 Tue	54	—	unknown	01:50–04:30 (good, 2.67 h)	87.2° 07:35	6.3	100%	104.6°
2034-05-03 Wed	51	—	unknown	01:50–04:30 (good, 2.67 h)	87.2° 07:30	6.24	100%	98.1°
2034-05-04 Thu	46	—	unknown	02:10–04:25 (good, 2.25 h)	87.2° 07:30	6.19	98%	91.4°
2034-05-05 Fri	44	—	unknown	02:25–04:25 (good, 2.0 h)	87.2° 07:25	6.13	95%	84.6°
2034-05-06 Sat	42	—	unknown	02:25–04:20 (good, 1.92 h)	87.2° 07:20	6.07	90%	77.9°
2034-05-07 Sun	43	—	unknown	02:00–04:20 (good, 2.33 h)	87.2° 07:15	6.02	83%	71.6°
2034-05-08 Mon	46	—	unknown	01:25–04:20 (good, 2.92 h)	87.2° 07:15	5.96	75%	65.8°
2034-05-09 Tue	56	—	unknown	00:55–04:15 (good, 3.33 h)	87.2° 07:10	5.9	66%	60.9°
2034-05-10 Wed	67	—	unknown	00:50–04:15 (good, 3.42 h)	87.2° 07:05	5.85	56%	57.3°
2034-05-11 Thu	76	—	unknown	00:45–04:15 (good, 3.5 h)	87.2° 07:00	5.79	45%	55.4°
2034-05-12 Fri	84	—	unknown	00:40–04:10 (good, 3.5 h)	87.2° 06:55	5.74	34%	55.6°
2034-05-13 Sat	91	—	unknown	00:40–04:10 (good, 3.5 h)	87.2° 06:55	5.68	24%	58.1°
2034-05-14 Sun	96	—	unknown	00:35–04:10 (good, 3.58 h)	87.2° 06:50	5.63	15%	62.8°
2034-05-15 Mon	97	—	unknown	00:30–04:05 (good, 3.58 h)	87.2° 06:45	5.57	7%	69.2°
2034-05-16 Tue	99	—	unknown	00:25–04:05 (good, 3.67 h)	87.2° 06:40	5.52	2%	76.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-04-17&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.