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: 09-21 (100), 09-22 (100), 09-23 (100), 09-24 (100), 09-25 (100) — by astronomy; check the weather when the night is within four days.

2033-09-21astronomy score per night — click a bar for that night2033-10-20

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2033-10-07 Fri	40	—	unknown	20:30–05:55 (marginal, 9.42 h)	79.1° 01:50	9.48	100%	31.7°
2033-10-08 Sat	31	—	unknown	20:25–23:55 (marginal, 3.5 h)	79.1° 01:45	9.52	100%	22.8°
2033-10-09 Sun	37	—	unknown	20:25–01:05 (marginal, 4.67 h)	79.1° 01:40	9.57	97%	22.1°
2033-10-10 Mon	72	—	unknown	20:20–20:30 (good, 0.17 h)	79.1° 01:35	9.61	91%	29.7°
2033-10-11 Tue	85	—	unknown	20:20–21:20 (good, 1.0 h)	79.1° 01:35	9.66	83%	41.0°
2033-10-12 Wed	92	—	unknown	20:20–02:30 (good, 6.17 h)	79.1° 01:30	9.7	74%	53.3°
2033-10-13 Thu	100	—	unknown	20:15–05:15 (good, 9.0 h)	79.1° 01:25	9.75	63%	65.8°
2033-10-14 Fri	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.79	53%	78.0°
2033-10-15 Sat	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:20	9.83	43%	90.0°
2033-10-16 Sun	100	—	unknown	20:15–06:05 (good, 9.83 h)	79.1° 01:15	9.88	33%	101.6°
2033-10-17 Mon	100	—	unknown	20:10–06:05 (good, 9.92 h)	79.1° 01:10	9.92	24%	112.9°
2033-10-18 Tue	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:05	9.96	16%	123.9°
2033-10-19 Wed	100	—	unknown	20:10–06:10 (good, 10.0 h)	79.1° 01:00	10.0	10%	134.5°
2033-10-20 Thu	100	—	unknown	20:05–06:10 (good, 10.08 h)	79.1° 01:00	10.05	5%	144.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-09-21&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.