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: 09-12 (100), 09-13 (100), 09-14 (100), 09-15 (100), 09-16 (100) — by astronomy; check the weather when the night is within four days.

2033-09-09astronomy score per night — click a bar for that night2033-10-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-09 Fri	62	—	unknown	21:20–21:50 (good, 0.5 h)	87.2° 23:05	8.07	99%	58.4°
2033-09-10 Sat	70	—	unknown	21:15–23:25 (good, 2.17 h)	87.2° 23:00	8.12	95%	64.0°
2033-09-11 Sun	77	—	unknown	21:15–01:55 (good, 4.67 h)	87.2° 22:55	8.18	88%	71.1°
2033-09-12 Mon	100	—	unknown	21:15–03:15 (good, 6.0 h)	87.2° 22:55	8.23	80%	79.0°
2033-09-13 Tue	100	—	unknown	21:10–04:30 (good, 7.33 h)	87.2° 22:50	8.28	70%	87.2°
2033-09-14 Wed	100	—	unknown	21:10–04:45 (good, 7.58 h)	87.2° 22:45	8.34	59%	95.3°
2033-09-15 Thu	100	—	unknown	21:05–04:45 (good, 7.67 h)	87.2° 22:40	8.39	48%	103.0°
2033-09-16 Fri	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.2° 22:35	8.44	37%	110.0°
2033-09-17 Sat	100	—	unknown	21:05–04:50 (good, 7.75 h)	87.2° 22:35	8.49	28%	116.0°
2033-09-18 Sun	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.2° 22:30	8.54	19%	120.8°
2033-09-19 Mon	100	—	unknown	21:00–04:45 (good, 7.75 h)	87.2° 22:25	8.6	12%	124.0°
2033-09-20 Tue	100	—	unknown	21:00–04:40 (good, 7.67 h)	87.2° 22:20	8.65	6%	125.5°
2033-09-21 Wed	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.2° 22:15	8.7	2%	125.2°
2033-09-22 Thu	100	—	unknown	20:55–04:35 (good, 7.67 h)	87.2° 22:15	8.75	0%	123.2°
2033-09-23 Fri	100	—	unknown	20:50–04:30 (good, 7.67 h)	87.2° 22:10	8.8	0%	119.6°
2033-09-24 Sat	100	—	unknown	20:50–04:25 (good, 7.58 h)	87.2° 22:05	8.85	2%	114.9°
2033-09-25 Sun	100	—	unknown	20:50–04:20 (good, 7.5 h)	87.2° 22:00	8.9	5%	109.2°
2033-09-26 Mon	100	—	unknown	20:45–04:20 (good, 7.58 h)	87.2° 21:55	8.95	10%	102.9°
2033-09-27 Tue	100	—	unknown	20:45–04:15 (good, 7.5 h)	87.2° 21:55	9.0	16%	96.2°
2033-09-28 Wed	100	—	unknown	20:45–04:10 (good, 7.42 h)	87.2° 21:50	9.05	24%	89.2°
2033-09-29 Thu	100	—	unknown	20:40–04:05 (good, 7.42 h)	87.2° 21:45	9.1	32%	82.2°
2033-09-30 Fri	100	—	unknown	20:40–04:00 (good, 7.33 h)	87.2° 21:40	9.15	42%	75.2°
2033-10-01 Sat	100	—	unknown	20:35–04:00 (good, 7.42 h)	87.2° 21:40	9.19	52%	68.6°
2033-10-02 Sun	93	—	unknown	20:35–03:55 (good, 7.33 h)	87.2° 21:35	9.24	63%	62.7°
2033-10-03 Mon	86	—	unknown	20:35–03:50 (good, 7.25 h)	87.2° 21:30	9.29	73%	58.0°
2033-10-04 Tue	68	—	unknown	23:20–01:35 (good, 2.25 h)	87.2° 21:25	9.34	83%	55.0°
2033-10-05 Wed	57	—	unknown	20:30–04:10 (marginal, 7.67 h)	87.2° 21:20	9.38	91%	54.5°
2033-10-06 Thu	55	—	unknown	20:30–03:55 (marginal, 7.42 h)	87.2° 21:20	9.43	96%	56.6°
2033-10-07 Fri	58	—	unknown	20:25–20:30 (good, 0.08 h)	87.2° 21:15	9.48	100%	61.2°
2033-10-08 Sat	67	—	unknown	20:25–21:55 (good, 1.5 h)	87.2° 21:10	9.52	100%	67.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-09&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.