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: 05-23 (100), 05-24 (100), 05-25 (100), 05-26 (100), 05-27 (100) — by astronomy; check the weather when the night is within four days.

2044-05-03astronomy score per night — click a bar for that night2044-06-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-05-03 Tue	82	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:30	6.21	44%	113.9°
2044-05-04 Wed	82	—	unknown	01:20–04:25 (good, 3.08 h)	87.2° 07:25	6.15	56%	118.4°
2044-05-05 Thu	84	—	unknown	01:15–04:25 (good, 3.17 h)	87.2° 07:25	6.1	66%	121.2°
2044-05-06 Fri	82	—	unknown	01:15–04:20 (good, 3.08 h)	87.2° 07:20	6.04	76%	122.0°
2044-05-07 Sat	82	—	unknown	01:10–04:20 (good, 3.17 h)	87.2° 07:15	5.98	84%	121.0°
2044-05-08 Sun	75	—	unknown	01:10–04:20 (good, 3.17 h)	87.2° 07:10	5.93	91%	118.4°
2044-05-09 Mon	71	—	unknown	01:10–04:15 (good, 3.08 h)	87.2° 07:05	5.87	96%	114.4°
2044-05-10 Tue	67	—	unknown	01:10–04:15 (good, 3.08 h)	87.2° 07:05	5.81	99%	109.4°
2044-05-11 Wed	64	—	unknown	01:10–04:15 (good, 3.08 h)	87.2° 07:00	5.76	100%	103.7°
2044-05-12 Thu	59	—	unknown	01:05–04:10 (good, 3.08 h)	87.2° 06:55	5.7	99%	97.5°
2044-05-13 Fri	57	—	unknown	01:05–04:10 (good, 3.08 h)	87.2° 06:50	5.65	96%	91.2°
2044-05-14 Sat	56	—	unknown	01:00–04:10 (good, 3.17 h)	87.2° 06:45	5.6	92%	84.9°
2044-05-15 Sun	56	—	unknown	00:55–04:05 (good, 3.17 h)	87.2° 06:45	5.54	86%	78.8°
2044-05-16 Mon	65	—	unknown	00:25–04:05 (good, 3.67 h)	87.2° 06:40	5.49	79%	73.1°
2044-05-17 Tue	72	—	unknown	00:20–04:05 (good, 3.75 h)	87.2° 06:35	5.44	71%	67.9°
2044-05-18 Wed	78	—	unknown	00:15–04:00 (good, 3.75 h)	87.2° 06:30	5.39	62%	63.5°
2044-05-19 Thu	85	—	unknown	00:10–04:00 (good, 3.83 h)	87.2° 06:30	5.34	52%	60.1°
2044-05-20 Fri	91	—	unknown	00:10–04:00 (good, 3.83 h)	87.2° 06:25	5.29	42%	58.2°
2044-05-21 Sat	97	—	unknown	00:05–03:55 (good, 3.83 h)	87.2° 06:20	5.24	32%	58.0°
2044-05-22 Sun	99	—	unknown	00:00–03:55 (good, 3.92 h)	87.2° 06:15	5.19	23%	59.6°
2044-05-23 Mon	100	—	unknown	23:55–03:55 (good, 4.0 h)	87.2° 06:10	5.14	14%	63.1°
2044-05-24 Tue	100	—	unknown	23:55–03:55 (good, 4.0 h)	87.2° 06:10	5.1	7%	68.3°
2044-05-25 Wed	100	—	unknown	23:50–03:50 (good, 4.0 h)	87.2° 06:05	5.05	2%	75.0°
2044-05-26 Thu	100	—	unknown	23:45–03:50 (good, 4.08 h)	87.2° 06:00	5.01	0%	82.5°
2044-05-27 Fri	100	—	unknown	23:40–03:50 (good, 4.17 h)	87.2° 05:55	4.97	1%	90.5°
2044-05-28 Sat	100	—	unknown	23:35–03:50 (good, 4.25 h)	87.2° 05:50	4.92	5%	98.5°
2044-05-29 Sun	100	—	unknown	23:35–03:50 (good, 4.25 h)	87.2° 05:50	4.88	11%	106.0°
2044-05-30 Mon	100	—	unknown	23:30–03:45 (good, 4.25 h)	87.2° 05:45	4.85	20%	112.5°
2044-05-31 Tue	100	—	unknown	23:30–03:45 (good, 4.25 h)	87.2° 05:40	4.81	30%	117.6°
2044-06-01 Wed	100	—	unknown	23:25–03:45 (good, 4.33 h)	87.2° 05:35	4.77	41%	120.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-05-03&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.