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: 05-17 (100), 05-18 (100), 05-19 (100), 05-20 (100), 05-21 (100) — by astronomy; check the weather when the night is within four days.

2029-04-22astronomy score per night — click a bar for that night2029-05-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-04-22 Sun	70	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:15	6.87	62%	122.9°
2029-04-23 Mon	70	—	unknown	02:05–04:45 (good, 2.67 h)	87.2° 08:10	6.81	73%	126.2°
2029-04-24 Tue	70	—	unknown	02:00–04:45 (good, 2.75 h)	87.2° 08:05	6.75	82%	127.0°
2029-04-25 Wed	63	—	unknown	02:00–04:40 (good, 2.67 h)	87.2° 08:05	6.7	90%	125.0°
2029-04-26 Thu	63	—	unknown	01:55–04:40 (good, 2.75 h)	87.2° 08:00	6.64	96%	120.5°
2029-04-27 Fri	59	—	unknown	02:00–04:40 (good, 2.67 h)	87.2° 07:55	6.58	99%	113.8°
2029-04-28 Sat	53	—	unknown	02:00–04:35 (good, 2.58 h)	87.2° 07:50	6.52	100%	105.8°
2029-04-29 Sun	49	—	unknown	02:00–04:35 (good, 2.58 h)	87.2° 07:45	6.46	97%	97.1°
2029-04-30 Mon	47	—	unknown	02:00–04:35 (good, 2.58 h)	87.2° 07:45	6.41	91%	88.4°
2029-05-01 Tue	45	—	unknown	01:55–04:30 (good, 2.58 h)	87.2° 07:40	6.35	84%	79.9°
2029-05-02 Wed	47	—	unknown	01:45–04:30 (good, 2.75 h)	87.2° 07:35	6.29	75%	72.1°
2029-05-03 Thu	53	—	unknown	01:15–04:25 (good, 3.17 h)	87.2° 07:30	6.23	65%	65.3°
2029-05-04 Fri	62	—	unknown	01:15–04:25 (good, 3.17 h)	87.2° 07:30	6.17	55%	59.7°
2029-05-05 Sat	69	—	unknown	01:10–04:25 (good, 3.25 h)	87.2° 07:25	6.12	45%	55.6°
2029-05-06 Sun	75	—	unknown	01:05–04:20 (good, 3.25 h)	87.2° 07:20	6.06	35%	53.4°
2029-05-07 Mon	80	—	unknown	01:00–04:20 (good, 3.33 h)	87.2° 07:15	6.0	26%	52.9°
2029-05-08 Tue	86	—	unknown	00:55–04:20 (good, 3.42 h)	87.2° 07:10	5.95	19%	54.4°
2029-05-09 Wed	89	—	unknown	00:55–04:15 (good, 3.33 h)	87.2° 07:10	5.89	12%	57.5°
2029-05-10 Thu	92	—	unknown	00:50–04:15 (good, 3.42 h)	87.2° 07:05	5.83	6%	61.9°
2029-05-11 Fri	93	—	unknown	00:45–04:15 (good, 3.5 h)	87.2° 07:00	5.78	3%	67.5°
2029-05-12 Sat	94	—	unknown	00:40–04:10 (good, 3.5 h)	87.2° 06:55	5.72	0%	73.9°
2029-05-13 Sun	96	—	unknown	00:35–04:10 (good, 3.58 h)	87.2° 06:50	5.67	0%	80.9°
2029-05-14 Mon	97	—	unknown	00:35–04:10 (good, 3.58 h)	87.2° 06:50	5.62	2%	88.2°
2029-05-15 Tue	97	—	unknown	00:30–04:05 (good, 3.58 h)	87.2° 06:45	5.56	5%	95.7°
2029-05-16 Wed	99	—	unknown	00:25–04:05 (good, 3.67 h)	87.2° 06:40	5.51	11%	103.1°
2029-05-17 Thu	100	—	unknown	00:20–04:05 (good, 3.75 h)	87.2° 06:35	5.46	18%	110.2°
2029-05-18 Fri	100	—	unknown	00:20–04:00 (good, 3.67 h)	87.2° 06:30	5.41	26%	116.6°
2029-05-19 Sat	100	—	unknown	00:15–04:00 (good, 3.75 h)	87.2° 06:30	5.36	36%	122.0°
2029-05-20 Sun	100	—	unknown	00:15–04:00 (good, 3.75 h)	87.2° 06:25	5.31	47%	125.7°
2029-05-21 Mon	100	—	unknown	00:15–04:00 (good, 3.75 h)	87.2° 06:20	5.26	58%	127.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-04-22&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.