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: 04-12 (63), 04-14 (63), 04-13 (62), 04-15 (62), 04-16 (62) — by astronomy; check the weather when the night is within four days.

2046-03-21astronomy score per night — click a bar for that night2046-04-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-03-21 Wed	35	—	unknown	03:20–04:50 (good, 1.5 h)	87.2° 09:20	8.66	100%	124.6°
2046-03-22 Thu	36	—	unknown	03:15–04:50 (good, 1.58 h)	87.1° 09:20	8.61	99%	121.6°
2046-03-23 Fri	34	—	unknown	03:15–04:45 (good, 1.5 h)	87.2° 09:15	8.56	96%	116.4°
2046-03-24 Sat	34	—	unknown	04:15–05:45 (good, 1.5 h)	87.2° 10:10	8.5	90%	109.8°
2046-03-25 Sun	33	—	unknown	04:10–05:45 (good, 1.58 h)	87.2° 10:05	8.45	83%	102.3°
2046-03-26 Mon	33	—	unknown	04:05–05:40 (good, 1.58 h)	87.2° 10:00	8.4	74%	94.6°
2046-03-27 Tue	34	—	unknown	04:00–05:40 (good, 1.67 h)	87.2° 10:00	8.35	64%	87.0°
2046-03-28 Wed	35	—	unknown	03:55–05:35 (good, 1.67 h)	87.2° 09:55	8.29	54%	79.7°
2046-03-29 Thu	39	—	unknown	03:35–05:35 (good, 2.0 h)	87.2° 09:50	8.24	44%	73.0°
2046-03-30 Fri	44	—	unknown	03:30–05:35 (good, 2.08 h)	87.2° 09:45	8.18	34%	67.0°
2046-03-31 Sat	48	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.13	25%	61.9°
2046-04-01 Sun	51	—	unknown	03:25–05:30 (good, 2.08 h)	87.2° 09:40	8.07	18%	58.1°
2046-04-02 Mon	52	—	unknown	03:20–05:25 (good, 2.08 h)	87.2° 09:35	8.02	11%	55.7°
2046-04-03 Tue	54	—	unknown	03:15–05:25 (good, 2.17 h)	87.2° 09:30	7.96	6%	54.9°
2046-04-04 Wed	56	—	unknown	03:10–05:25 (good, 2.25 h)	87.2° 09:25	7.91	2%	55.8°
2046-04-05 Thu	56	—	unknown	03:05–05:20 (good, 2.25 h)	87.1° 09:25	7.85	0%	58.4°
2046-04-06 Fri	57	—	unknown	03:05–05:20 (good, 2.25 h)	87.2° 09:20	7.8	0%	62.4°
2046-04-07 Sat	57	—	unknown	03:00–05:15 (good, 2.25 h)	87.2° 09:15	7.74	2%	67.6°
2046-04-08 Sun	58	—	unknown	02:55–05:15 (good, 2.33 h)	87.2° 09:10	7.68	6%	73.7°
2046-04-09 Mon	60	—	unknown	02:50–05:15 (good, 2.42 h)	87.2° 09:05	7.63	11%	80.5°
2046-04-10 Tue	59	—	unknown	02:50–05:10 (good, 2.33 h)	87.2° 09:05	7.57	18%	87.7°
2046-04-11 Wed	61	—	unknown	02:45–05:10 (good, 2.42 h)	87.2° 09:00	7.51	27%	95.1°
2046-04-12 Thu	63	—	unknown	02:40–05:10 (good, 2.5 h)	87.2° 08:55	7.46	37%	102.5°
2046-04-13 Fri	62	—	unknown	02:40–05:05 (good, 2.42 h)	87.2° 08:50	7.4	48%	109.6°
2046-04-14 Sat	63	—	unknown	02:40–05:05 (good, 2.42 h)	87.2° 08:45	7.34	59%	116.0°
2046-04-15 Sun	62	—	unknown	02:35–05:00 (good, 2.42 h)	87.2° 08:45	7.28	70%	121.1°
2046-04-16 Mon	62	—	unknown	02:35–05:00 (good, 2.42 h)	87.2° 08:40	7.23	80%	124.3°
2046-04-17 Tue	62	—	unknown	02:30–05:00 (good, 2.5 h)	87.2° 08:35	7.17	88%	125.2°
2046-04-18 Wed	57	—	unknown	02:30–04:55 (good, 2.42 h)	87.2° 08:30	7.11	95%	123.3°
2046-04-19 Thu	55	—	unknown	02:25–04:55 (good, 2.5 h)	87.1° 08:30	7.05	99%	119.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-03-21&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.