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: 11-05 (100), 11-06 (100), 11-07 (100), 11-08 (100), 11-09 (100) — by astronomy; check the weather when the night is within four days.

2028-10-27astronomy score per night — click a bar for that night2028-11-25

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-27 Fri	62	—	unknown	20:00–23:40 (good, 3.67 h)	87.2° 19:55	10.33	75%	53.9°
2028-10-28 Sat	54	—	unknown	19:55–02:40 (marginal, 6.75 h)	87.2° 19:50	10.37	82%	53.4°
2028-10-29 Sun	47	—	unknown	18:55–01:25 (marginal, 6.5 h)	87.2° 18:45	10.41	89%	54.8°
2028-10-30 Mon	44	—	unknown	18:55–01:10 (marginal, 6.25 h)	87.2° 18:45	10.45	94%	57.9°
2028-10-31 Tue	46	—	unknown	18:55–01:00 (marginal, 6.08 h)	87.2° 18:40	10.48	98%	62.3°
2028-11-01 Wed	52	—	unknown	18:50–19:25 (good, 0.58 h)	87.2° 18:35	10.52	100%	68.0°
2028-11-02 Thu	62	—	unknown	18:50–20:55 (good, 2.08 h)	87.2° 18:30	10.56	100%	74.5°
2028-11-03 Fri	74	—	unknown	18:50–22:00 (good, 3.17 h)	87.2° 18:25	10.59	98%	81.6°
2028-11-04 Sat	81	—	unknown	18:50–23:05 (good, 4.25 h)	87.2° 18:25	10.63	94%	89.1°
2028-11-05 Sun	100	—	unknown	18:50–00:05 (good, 5.25 h)	87.2° 18:20	10.66	88%	96.7°
2028-11-06 Mon	100	—	unknown	18:45–00:15 (good, 5.5 h)	87.2° 18:15	10.69	80%	104.3°
2028-11-07 Tue	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:10	10.73	71%	111.4°
2028-11-08 Wed	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:05	10.76	61%	117.7°
2028-11-09 Thu	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:05	10.79	50%	122.8°
2028-11-10 Fri	100	—	unknown	18:45–00:20 (good, 5.58 h)	87.2° 18:00	10.82	38%	125.9°
2028-11-11 Sat	100	—	unknown	18:40–00:15 (good, 5.58 h)	87.2° 17:55	10.86	28%	126.7°
2028-11-12 Sun	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.89	18%	124.7°
2028-11-13 Mon	100	—	unknown	18:40–00:10 (good, 5.5 h)	87.2° 17:50	10.92	10%	120.3°
2028-11-14 Tue	100	—	unknown	18:40–00:05 (good, 5.42 h)	87.2° 17:45	10.95	4%	114.0°
2028-11-15 Wed	100	—	unknown	18:40–00:00 (good, 5.33 h)	87.2° 17:40	10.97	1%	106.4°
2028-11-16 Thu	100	—	unknown	18:40–23:55 (good, 5.25 h)	87.2° 17:35	11.0	0%	98.2°
2028-11-17 Fri	100	—	unknown	18:40–23:50 (good, 5.17 h)	87.2° 17:30	11.03	2%	89.7°
2028-11-18 Sat	100	—	unknown	18:35–23:50 (good, 5.25 h)	87.2° 17:30	11.06	7%	81.5°
2028-11-19 Sun	100	—	unknown	18:35–23:45 (good, 5.17 h)	87.2° 17:25	11.08	14%	73.8°
2028-11-20 Mon	97	—	unknown	18:35–23:40 (good, 5.08 h)	87.2° 17:20	11.11	21%	67.0°
2028-11-21 Tue	89	—	unknown	18:35–23:35 (good, 5.0 h)	87.2° 17:15	11.13	30%	61.3°
2028-11-22 Wed	83	—	unknown	18:35–23:30 (good, 4.92 h)	87.2° 17:10	11.16	40%	56.9°
2028-11-23 Thu	76	—	unknown	18:35–23:10 (good, 4.58 h)	87.2° 17:10	11.18	49%	54.2°
2028-11-24 Fri	62	—	unknown	18:35–22:50 (good, 4.25 h)	87.2° 17:05	11.2	59%	53.2°
2028-11-25 Sat	50	—	unknown	18:35–20:30 (good, 1.92 h)	87.2° 17:00	11.22	68%	54.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-27&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.