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: 04-28 (78), 04-27 (77), 04-26 (76), 04-25 (75), 04-24 (74) — by astronomy; check the weather when the night is within four days.

2028-03-30astronomy score per night — click a bar for that night2028-04-28

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-30 Thu	50	—	unknown	03:30–05:30 (good, 2.0 h)	87.2° 09:45	8.16	21%	84.4°
2028-03-31 Fri	52	—	unknown	03:25–05:30 (good, 2.08 h)	87.3° 09:40	8.11	30%	92.0°
2028-04-01 Sat	54	—	unknown	03:20–05:30 (good, 2.17 h)	87.2° 09:35	8.05	40%	99.7°
2028-04-02 Sun	53	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	8.0	51%	107.3°
2028-04-03 Mon	53	—	unknown	03:20–05:25 (good, 2.08 h)	87.2° 09:30	7.94	63%	114.2°
2028-04-04 Tue	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:25	7.89	73%	120.1°
2028-04-05 Wed	53	—	unknown	03:15–05:20 (good, 2.08 h)	87.3° 09:20	7.83	83%	124.2°
2028-04-06 Thu	49	—	unknown	03:15–05:20 (good, 2.08 h)	87.2° 09:15	7.78	91%	125.9°
2028-04-07 Fri	47	—	unknown	03:10–05:15 (good, 2.08 h)	87.2° 09:15	7.72	97%	124.9°
2028-04-08 Sat	48	—	unknown	03:05–05:15 (good, 2.17 h)	87.2° 09:10	7.66	100%	121.3°
2028-04-09 Sun	46	—	unknown	03:05–05:15 (good, 2.17 h)	87.3° 09:05	7.61	100%	115.6°
2028-04-10 Mon	43	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 09:00	7.55	97%	108.6°
2028-04-11 Tue	41	—	unknown	03:05–05:10 (good, 2.08 h)	87.2° 08:55	7.49	92%	101.0°
2028-04-12 Wed	40	—	unknown	03:05–05:05 (good, 2.0 h)	87.2° 08:55	7.44	85%	93.1°
2028-04-13 Thu	40	—	unknown	03:00–05:05 (good, 2.08 h)	87.2° 08:50	7.38	76%	85.3°
2028-04-14 Fri	42	—	unknown	02:50–05:05 (good, 2.25 h)	87.3° 08:45	7.32	67%	78.0°
2028-04-15 Sat	45	—	unknown	02:45–05:00 (good, 2.25 h)	87.2° 08:40	7.26	57%	71.2°
2028-04-16 Sun	52	—	unknown	02:20–05:00 (good, 2.67 h)	87.2° 08:35	7.21	48%	65.3°
2028-04-17 Mon	56	—	unknown	02:20–04:55 (good, 2.58 h)	87.2° 08:35	7.15	38%	60.4°
2028-04-18 Tue	62	—	unknown	02:15–04:55 (good, 2.67 h)	87.3° 08:30	7.09	29%	56.7°
2028-04-19 Wed	66	—	unknown	02:10–04:55 (good, 2.75 h)	87.3° 08:25	7.03	21%	54.5°
2028-04-20 Thu	69	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:20	6.97	14%	54.0°
2028-04-21 Fri	71	—	unknown	02:05–04:50 (good, 2.75 h)	87.2° 08:20	6.92	8%	55.4°
2028-04-22 Sat	71	—	unknown	02:00–04:45 (good, 2.75 h)	87.2° 08:15	6.86	4%	58.4°
2028-04-23 Sun	73	—	unknown	01:55–04:45 (good, 2.83 h)	87.3° 08:10	6.8	1%	62.9°
2028-04-24 Mon	74	—	unknown	01:50–04:45 (good, 2.92 h)	87.2° 08:05	6.74	0%	68.7°
2028-04-25 Tue	75	—	unknown	01:45–04:40 (good, 2.92 h)	87.2° 08:00	6.68	1%	75.3°
2028-04-26 Wed	76	—	unknown	01:45–04:40 (good, 2.92 h)	87.2° 08:00	6.62	5%	82.7°
2028-04-27 Thu	77	—	unknown	01:40–04:40 (good, 3.0 h)	87.2° 07:55	6.57	10%	90.4°
2028-04-28 Fri	78	—	unknown	01:35–04:35 (good, 3.0 h)	87.3° 07:50	6.51	18%	98.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-30&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.