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 Triangulum Pinwheel: 09-16 (100), 09-17 (100), 09-18 (100), 09-19 (100), 09-20 (100) — by astronomy; check the weather when the night is within four days.

2033-09-07astronomy score per night — click a bar for that night2033-10-06

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-09-07 Wed	70	—	unknown	02:55–05:20 (good, 2.42 h)	79.1° 03:45	7.96	98%	64.3°
2033-09-08 Thu	51	—	unknown	22:15–05:20 (marginal, 7.08 h)	79.1° 03:45	8.01	100%	50.8°
2033-09-09 Fri	33	—	unknown	22:15–05:25 (marginal, 7.17 h)	79.1° 03:40	8.07	99%	37.9°
2033-09-10 Sat	26	—	unknown	22:05–05:25 (marginal, 7.33 h)	79.1° 03:35	8.12	95%	26.9°
2033-09-11 Sun	35	—	unknown	21:50–05:25 (marginal, 7.58 h)	79.1° 03:30	8.18	88%	21.2°
2033-09-12 Mon	52	—	unknown	21:30–05:25 (marginal, 7.92 h)	79.1° 03:30	8.23	80%	24.5°
2033-09-13 Tue	82	—	unknown	22:50–01:25 (good, 2.58 h)	79.1° 03:25	8.28	70%	33.8°
2033-09-14 Wed	88	—	unknown	21:50–05:30 (good, 7.67 h)	79.1° 03:20	8.34	59%	45.2°
2033-09-15 Thu	95	—	unknown	21:50–05:30 (good, 7.67 h)	79.1° 03:15	8.39	48%	57.2°
2033-09-16 Fri	100	—	unknown	21:45–05:30 (good, 7.75 h)	79.1° 03:10	8.44	37%	69.3°
2033-09-17 Sat	100	—	unknown	21:40–05:35 (good, 7.92 h)	79.1° 03:10	8.49	28%	81.2°
2033-09-18 Sun	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:05	8.54	19%	92.9°
2033-09-19 Mon	100	—	unknown	21:35–05:35 (good, 8.0 h)	79.1° 03:00	8.6	12%	104.4°
2033-09-20 Tue	100	—	unknown	21:30–05:35 (good, 8.08 h)	79.1° 02:55	8.65	6%	115.7°
2033-09-21 Wed	100	—	unknown	21:25–05:40 (good, 8.25 h)	79.1° 02:50	8.7	2%	126.6°
2033-09-22 Thu	100	—	unknown	21:20–05:40 (good, 8.33 h)	79.1° 02:50	8.75	0%	137.1°
2033-09-23 Fri	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:45	8.8	0%	146.7°
2033-09-24 Sat	100	—	unknown	21:15–05:40 (good, 8.42 h)	79.1° 02:40	8.85	2%	154.5°
2033-09-25 Sun	100	—	unknown	21:10–05:40 (good, 8.5 h)	79.1° 02:35	8.9	5%	158.6°
2033-09-26 Mon	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.1° 02:30	8.95	10%	157.0°
2033-09-27 Tue	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:30	9.0	16%	150.5°
2033-09-28 Wed	100	—	unknown	21:00–05:45 (good, 8.75 h)	79.1° 02:25	9.05	24%	141.4°
2033-09-29 Thu	100	—	unknown	20:55–05:45 (good, 8.83 h)	79.1° 02:20	9.1	32%	131.0°
2033-09-30 Fri	100	—	unknown	20:55–05:50 (good, 8.92 h)	79.1° 02:15	9.15	42%	119.9°
2033-10-01 Sat	100	—	unknown	20:55–05:50 (good, 8.92 h)	79.1° 02:15	9.19	52%	108.2°
2033-10-02 Sun	100	—	unknown	20:55–05:50 (good, 8.92 h)	79.1° 02:10	9.24	63%	96.0°
2033-10-03 Mon	100	—	unknown	21:05–05:50 (good, 8.75 h)	79.1° 02:05	9.29	73%	83.3°
2033-10-04 Tue	100	—	unknown	22:30–05:50 (good, 7.33 h)	79.1° 02:00	9.34	83%	70.2°
2033-10-05 Wed	97	—	unknown	01:55–05:55 (good, 4.0 h)	79.1° 01:55	9.38	91%	56.9°
2033-10-06 Thu	88	—	unknown	05:50–05:55 (good, 0.08 h)	79.1° 01:55	9.43	96%	43.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-07&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.