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: 02-10 (100), 02-11 (100), 02-12 (100), 02-13 (100), 02-14 (100) — by astronomy; check the weather when the night is within four days.

2045-02-10astronomy score per night — click a bar for that night2045-03-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-02-10 Fri	100	—	unknown	19:25–23:55 (good, 4.5 h)	72.6° 18:45	10.42	30%	162.9°
2045-02-11 Sat	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:40	10.39	21%	151.0°
2045-02-12 Sun	100	—	unknown	19:25–23:50 (good, 4.42 h)	72.6° 18:40	10.35	14%	139.2°
2045-02-13 Mon	100	—	unknown	19:30–23:45 (good, 4.25 h)	72.6° 18:35	10.31	8%	127.3°
2045-02-14 Tue	100	—	unknown	19:30–23:40 (good, 4.17 h)	72.6° 18:30	10.27	4%	115.5°
2045-02-15 Wed	100	—	unknown	19:30–23:35 (good, 4.08 h)	72.6° 18:25	10.23	1%	103.7°
2045-02-16 Thu	100	—	unknown	19:30–23:35 (good, 4.08 h)	72.6° 18:20	10.19	0%	91.7°
2045-02-17 Fri	100	—	unknown	19:35–23:30 (good, 3.92 h)	72.6° 18:20	10.15	1%	79.6°
2045-02-18 Sat	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.6° 18:15	10.11	4%	67.4°
2045-02-19 Sun	95	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:10	10.07	8%	55.1°
2045-02-20 Mon	87	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:05	10.02	14%	42.5°
2045-02-21 Tue	74	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:00	9.98	22%	29.8°
2045-02-22 Wed	59	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 18:00	9.94	32%	16.8°
2045-02-23 Thu	46	—	unknown	19:40–22:40 (good, 3.0 h)	72.6° 17:55	9.9	42%	3.7°
2045-02-24 Fri	33	—	unknown	19:40–23:25 (marginal, 3.75 h)	72.6° 17:50	9.85	53%	10.1°
2045-02-25 Sat	22	—	unknown	19:40–23:10 (marginal, 3.5 h)	72.6° 17:45	9.81	64%	24.0°
2045-02-26 Sun	18	—	unknown	19:45–22:50 (marginal, 3.08 h)	72.6° 17:45	9.76	74%	38.3°
2045-02-27 Mon	19	—	unknown	19:45–22:45 (marginal, 3.0 h)	72.6° 17:40	9.72	84%	52.9°
2045-02-28 Tue	24	—	unknown	19:45–22:50 (marginal, 3.08 h)	72.6° 17:35	9.67	92%	67.7°
2045-03-01 Wed	32	—	unknown	19:45–20:30 (good, 0.75 h)	72.6° 17:30	9.63	97%	82.7°
2045-03-02 Thu	42	—	unknown	19:50–21:50 (good, 2.0 h)	72.6° 17:25	9.58	100%	97.7°
2045-03-03 Fri	52	—	unknown	19:50–22:15 (good, 2.42 h)	72.6° 17:25	9.54	99%	112.5°
2045-03-04 Sat	62	—	unknown	19:50–22:20 (good, 2.5 h)	72.6° 17:20	9.49	96%	127.0°
2045-03-05 Sun	64	—	unknown	19:50–22:20 (good, 2.5 h)	72.6° 17:15	9.44	91%	141.1°
2045-03-06 Mon	64	—	unknown	19:50–22:20 (good, 2.5 h)	72.6° 17:10	9.4	84%	154.7°
2045-03-07 Tue	61	—	unknown	19:55–22:20 (good, 2.42 h)	72.6° 17:05	9.35	75%	167.9°
2045-03-08 Wed	59	—	unknown	19:55–22:15 (good, 2.33 h)	72.6° 17:05	9.3	66%	178.6°
2045-03-09 Thu	57	—	unknown	19:55–22:10 (good, 2.25 h)	72.6° 17:00	9.25	56%	166.7°
2045-03-10 Fri	55	—	unknown	19:55–22:05 (good, 2.17 h)	72.6° 16:55	9.2	46%	154.6°
2045-03-11 Sat	52	—	unknown	20:00–22:00 (good, 2.0 h)	72.6° 16:50	9.16	37%	142.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-02-10&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.