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: 03-10 (14), 03-11 (11), 03-12 (9), 03-13 (8), 03-14 (7) — by astronomy; check the weather when the night is within four days.

2037-03-10astronomy score per night — click a bar for that night2037-04-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-03-10 Tue	14	—	unknown	19:55–20:15 (good, 0.33 h)	79.1° 14:45	9.21	29%	106.5°
2037-03-11 Wed	11	—	unknown	20:00–20:10 (good, 0.17 h)	79.2° 14:40	9.16	21%	95.5°
2037-03-12 Thu	9	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:35	9.11	14%	84.7°
2037-03-13 Fri	8	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:30	9.06	8%	74.0°
2037-03-14 Sat	7	—	unknown	19:30–20:30 (marginal, 1.0 h)	79.1° 14:25	9.01	4%	63.4°
2037-03-15 Sun	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.2° 14:25	8.96	1%	53.1°
2037-03-16 Mon	4	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.2° 14:20	8.91	0%	43.3°
2037-03-17 Tue	3	—	unknown	19:35–19:50 (marginal, 0.25 h)	79.2° 14:15	8.86	1%	34.4°
2037-03-18 Wed	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:10	8.81	4%	27.5°
2037-03-19 Thu	2	—	unknown	—	79.1° 14:05	8.76	8%	24.5°
2037-03-20 Fri	1	—	unknown	—	79.2° 14:05	8.7	14%	26.9°
2037-03-21 Sat	1	—	unknown	—	79.2° 14:00	8.65	22%	33.9°
2037-03-22 Sun	0	—	unknown	—	79.2° 13:55	8.6	31%	43.3°
2037-03-23 Mon	0	—	unknown	—	79.2° 13:50	8.55	41%	54.2°
2037-03-24 Tue	0	—	unknown	—	79.1° 13:50	8.5	52%	65.9°
2037-03-25 Wed	0	—	unknown	—	79.2° 13:45	8.44	63%	78.3°
2037-03-26 Thu	0	—	unknown	—	79.2° 13:40	8.39	73%	91.1°
2037-03-27 Fri	0	—	unknown	—	79.2° 13:35	8.34	83%	104.3°
2037-03-28 Sat	0	—	unknown	—	79.1° 13:30	8.28	91%	117.6°
2037-03-29 Sun	0	—	unknown	—	79.2° 14:30	8.23	97%	130.6°
2037-03-30 Mon	0	—	unknown	—	79.2° 14:25	8.17	100%	142.6°
2037-03-31 Tue	0	—	unknown	—	79.2° 14:20	8.12	99%	152.0°
2037-04-01 Wed	0	—	unknown	—	79.2° 14:15	8.06	96%	155.6°
2037-04-02 Thu	0	—	unknown	—	79.1° 14:10	8.01	91%	151.6°
2037-04-03 Fri	0	—	unknown	—	79.2° 14:10	7.95	84%	142.9°
2037-04-04 Sat	0	—	unknown	—	79.2° 14:05	7.9	75%	132.3°
2037-04-05 Sun	0	—	unknown	—	79.2° 14:00	7.84	65%	121.1°
2037-04-06 Mon	0	—	unknown	—	79.2° 13:55	7.79	55%	109.9°
2037-04-07 Tue	0	—	unknown	—	79.1° 13:55	7.73	46%	98.8°
2037-04-08 Wed	0	—	unknown	—	79.2° 13:50	7.67	36%	87.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-03-10&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.