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 Seven Sisters: 03-06 (48), 03-07 (38), 03-19 (33), 03-20 (33), 03-21 (32) — by astronomy; check the weather when the night is within four days.

2041-03-06astronomy score per night — click a bar for that night2041-04-04

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2041-03-06 Wed	48	—	unknown	19:50–22:10 (good, 2.33 h)	72.5° 17:10	9.4	23%	16.0°
2041-03-07 Thu	38	—	unknown	19:55–22:00 (good, 2.08 h)	72.5° 17:05	9.35	33%	3.8°
2041-03-08 Fri	29	—	unknown	19:55–21:15 (good, 1.33 h)	72.5° 17:05	9.3	43%	10.8°
2041-03-09 Sat	21	—	unknown	19:55–22:30 (marginal, 2.58 h)	72.5° 17:00	9.25	53%	23.1°
2041-03-10 Sun	16	—	unknown	19:55–22:15 (marginal, 2.33 h)	72.5° 16:55	9.21	62%	35.2°
2041-03-11 Mon	14	—	unknown	20:00–22:10 (marginal, 2.17 h)	72.5° 16:50	9.16	71%	47.2°
2041-03-12 Tue	15	—	unknown	20:00–22:05 (marginal, 2.08 h)	72.5° 16:45	9.11	80%	59.0°
2041-03-13 Wed	16	—	unknown	20:00–22:05 (marginal, 2.08 h)	72.5° 16:45	9.06	86%	70.8°
2041-03-14 Thu	19	—	unknown	20:00–22:05 (marginal, 2.08 h)	72.5° 16:40	9.01	92%	82.6°
2041-03-15 Fri	22	—	unknown	20:05–20:45 (good, 0.67 h)	72.5° 16:35	8.96	96%	94.5°
2041-03-16 Sat	27	—	unknown	20:05–21:20 (good, 1.25 h)	72.5° 16:30	8.91	99%	106.4°
2041-03-17 Sun	30	—	unknown	20:05–21:25 (good, 1.33 h)	72.5° 16:30	8.86	100%	118.5°
2041-03-18 Mon	31	—	unknown	20:05–21:25 (good, 1.33 h)	72.5° 16:25	8.81	99%	130.7°
2041-03-19 Tue	33	—	unknown	20:10–21:25 (good, 1.25 h)	72.5° 16:20	8.75	96%	143.1°
2041-03-20 Wed	33	—	unknown	20:10–21:25 (good, 1.25 h)	72.5° 16:15	8.7	91%	155.6°
2041-03-21 Thu	32	—	unknown	20:10–21:25 (good, 1.25 h)	72.5° 16:10	8.65	84%	168.2°
2041-03-22 Fri	30	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:10	8.6	76%	176.8°
2041-03-23 Sat	27	—	unknown	20:15–21:15 (good, 1.0 h)	72.5° 16:05	8.55	66%	165.0°
2041-03-24 Sun	26	—	unknown	20:15–21:10 (good, 0.92 h)	72.5° 16:00	8.49	56%	151.6°
2041-03-25 Mon	25	—	unknown	20:15–21:05 (good, 0.83 h)	72.5° 15:55	8.44	44%	137.9°
2041-03-26 Tue	23	—	unknown	20:15–21:05 (good, 0.83 h)	72.5° 15:50	8.39	33%	123.8°
2041-03-27 Wed	21	—	unknown	20:20–21:00 (good, 0.67 h)	72.5° 15:50	8.33	23%	109.4°
2041-03-28 Thu	20	—	unknown	20:20–20:55 (good, 0.58 h)	72.5° 15:45	8.28	14%	94.7°
2041-03-29 Fri	18	—	unknown	20:20–20:50 (good, 0.5 h)	72.5° 15:40	8.23	7%	80.0°
2041-03-30 Sat	16	—	unknown	20:20–20:50 (good, 0.5 h)	72.5° 15:35	8.17	2%	65.1°
2041-03-31 Sun	13	—	unknown	21:25–21:45 (good, 0.33 h)	72.5° 16:35	8.12	0%	50.4°
2041-04-01 Mon	12	—	unknown	21:25–21:40 (good, 0.25 h)	72.5° 16:30	8.06	1%	35.9°
2041-04-02 Tue	10	—	unknown	21:25–21:35 (good, 0.17 h)	72.5° 16:25	8.01	5%	21.8°
2041-04-03 Wed	7	—	unknown	21:30–22:00 (marginal, 0.5 h)	72.5° 16:20	7.95	10%	8.3°
2041-04-04 Thu	6	—	unknown	21:30–21:55 (marginal, 0.42 h)	72.5° 16:15	7.9	18%	6.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2041-03-06&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.