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: 08-30 (100), 08-31 (100), 09-01 (100), 09-02 (100), 09-03 (100) — by astronomy; check the weather when the night is within four days.

2043-08-28astronomy score per night — click a bar for that night2043-09-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-08-28 Fri	88	—	unknown	23:00–05:05 (good, 6.08 h)	79.2° 04:30	7.38	34%	51.2°
2043-08-29 Sat	96	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:25	7.44	24%	64.4°
2043-08-30 Sun	100	—	unknown	22:55–05:10 (good, 6.25 h)	79.2° 04:20	7.49	15%	77.7°
2043-08-31 Mon	100	—	unknown	22:50–05:10 (good, 6.33 h)	79.2° 04:15	7.55	8%	90.9°
2043-09-01 Tue	100	—	unknown	22:45–05:10 (good, 6.42 h)	79.2° 04:15	7.6	3%	104.0°
2043-09-02 Wed	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.2° 04:10	7.66	0%	116.8°
2043-09-03 Thu	100	—	unknown	22:40–05:15 (good, 6.58 h)	79.2° 04:05	7.72	0%	129.2°
2043-09-04 Fri	100	—	unknown	22:35–05:15 (good, 6.67 h)	79.2° 04:00	7.77	2%	141.0°
2043-09-05 Sat	100	—	unknown	22:30–05:15 (good, 6.75 h)	79.2° 03:55	7.83	6%	151.7°
2043-09-06 Sun	100	—	unknown	22:25–05:20 (good, 6.92 h)	79.2° 03:55	7.88	11%	160.4°
2043-09-07 Mon	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.2° 03:50	7.94	18%	163.6°
2043-09-08 Tue	100	—	unknown	22:20–05:20 (good, 7.0 h)	79.2° 03:45	7.99	26%	159.1°
2043-09-09 Wed	100	—	unknown	22:15–05:20 (good, 7.08 h)	79.2° 03:40	8.05	35%	150.4°
2043-09-10 Thu	100	—	unknown	22:15–05:25 (good, 7.17 h)	79.2° 03:40	8.1	44%	140.2°
2043-09-11 Fri	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:35	8.15	54%	129.3°
2043-09-12 Sat	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:30	8.21	63%	118.0°
2043-09-13 Sun	100	—	unknown	22:10–05:25 (good, 7.25 h)	79.2° 03:25	8.26	72%	106.3°
2043-09-14 Mon	100	—	unknown	22:15–05:30 (good, 7.25 h)	79.2° 03:20	8.31	81%	94.3°
2043-09-15 Tue	100	—	unknown	22:40–05:30 (good, 6.83 h)	79.2° 03:20	8.37	88%	82.0°
2043-09-16 Wed	100	—	unknown	00:20–05:30 (good, 5.17 h)	79.2° 03:15	8.42	94%	69.3°
2043-09-17 Thu	67	—	unknown	04:00–05:30 (good, 1.5 h)	79.2° 03:10	8.47	98%	56.4°
2043-09-18 Fri	49	—	unknown	21:40–05:35 (marginal, 7.92 h)	79.2° 03:05	8.52	100%	43.4°
2043-09-19 Sat	29	—	unknown	21:40–01:30 (marginal, 3.83 h)	79.2° 03:00	8.57	99%	30.8°
2043-09-20 Sun	28	—	unknown	21:25–01:55 (marginal, 4.5 h)	79.2° 03:00	8.63	95%	20.2°
2043-09-21 Mon	36	—	unknown	21:15–05:35 (marginal, 8.33 h)	79.2° 02:55	8.68	89%	16.6°
2043-09-22 Tue	50	—	unknown	20:55–05:40 (marginal, 8.75 h)	79.2° 02:50	8.73	81%	23.6°
2043-09-23 Wed	77	—	unknown	23:15–00:35 (good, 1.33 h)	79.2° 02:45	8.78	71%	35.2°
2043-09-24 Thu	85	—	unknown	21:15–05:20 (good, 8.08 h)	79.2° 02:45	8.83	60%	48.1°
2043-09-25 Fri	93	—	unknown	21:10–05:40 (good, 8.5 h)	79.2° 02:40	8.88	48%	61.3°
2043-09-26 Sat	100	—	unknown	21:05–05:45 (good, 8.67 h)	79.2° 02:35	8.93	37%	74.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-08-28&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.