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: 03-03 (66), 03-04 (66), 03-05 (66), 03-06 (64), 03-07 (61) — by astronomy; check the weather when the night is within four days.

2037-02-25astronomy score per night — click a bar for that night2037-03-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2037-02-25 Wed	19	—	unknown	19:40–22:55 (marginal, 3.25 h)	72.5° 17:45	9.81	78%	41.8°
2037-02-26 Thu	21	—	unknown	19:45–22:55 (marginal, 3.17 h)	72.5° 17:40	9.77	86%	55.9°
2037-02-27 Fri	26	—	unknown	19:45–22:55 (marginal, 3.17 h)	72.5° 17:40	9.72	94%	70.5°
2037-02-28 Sat	35	—	unknown	19:45–20:50 (good, 1.08 h)	72.5° 17:35	9.68	98%	85.5°
2037-03-01 Sun	47	—	unknown	19:45–22:10 (good, 2.42 h)	72.5° 17:30	9.63	100%	100.6°
2037-03-02 Mon	56	—	unknown	19:50–22:25 (good, 2.58 h)	72.5° 17:25	9.59	99%	115.6°
2037-03-03 Tue	66	—	unknown	19:50–22:25 (good, 2.58 h)	72.5° 17:25	9.54	94%	130.4°
2037-03-04 Wed	66	—	unknown	19:50–22:20 (good, 2.5 h)	72.5° 17:20	9.49	88%	144.7°
2037-03-05 Thu	66	—	unknown	19:50–22:25 (good, 2.58 h)	72.5° 17:15	9.45	79%	158.2°
2037-03-06 Fri	64	—	unknown	19:50–22:20 (good, 2.5 h)	72.5° 17:10	9.4	69%	169.2°
2037-03-07 Sat	61	—	unknown	19:55–22:20 (good, 2.42 h)	72.5° 17:05	9.35	59%	168.6°
2037-03-08 Sun	59	—	unknown	19:55–22:15 (good, 2.33 h)	72.5° 17:05	9.3	49%	158.1°
2037-03-09 Mon	56	—	unknown	19:55–22:10 (good, 2.25 h)	72.5° 17:00	9.26	39%	146.3°
2037-03-10 Tue	55	—	unknown	19:55–22:05 (good, 2.17 h)	72.5° 16:55	9.21	29%	134.4°
2037-03-11 Wed	52	—	unknown	20:00–22:00 (good, 2.0 h)	72.5° 16:50	9.16	21%	122.5°
2037-03-12 Thu	50	—	unknown	20:00–22:00 (good, 2.0 h)	72.5° 16:45	9.11	14%	110.8°
2037-03-13 Fri	47	—	unknown	20:00–21:55 (good, 1.92 h)	72.5° 16:45	9.06	8%	99.1°
2037-03-14 Sat	46	—	unknown	20:00–21:50 (good, 1.83 h)	72.5° 16:40	9.01	4%	87.4°
2037-03-15 Sun	43	—	unknown	20:05–21:45 (good, 1.67 h)	72.5° 16:35	8.96	1%	75.8°
2037-03-16 Mon	41	—	unknown	20:05–21:40 (good, 1.58 h)	72.5° 16:30	8.91	0%	64.1°
2037-03-17 Tue	39	—	unknown	20:05–21:40 (good, 1.58 h)	72.5° 16:30	8.86	1%	52.3°
2037-03-18 Wed	37	—	unknown	20:05–21:35 (good, 1.5 h)	72.5° 16:25	8.81	4%	40.5°
2037-03-19 Thu	33	—	unknown	20:10–21:30 (good, 1.33 h)	72.5° 16:20	8.76	8%	28.8°
2037-03-20 Fri	29	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:15	8.7	14%	17.5°
2037-03-21 Sat	24	—	unknown	20:10–21:10 (good, 1.0 h)	72.5° 16:10	8.65	22%	9.2°
2037-03-22 Sun	19	—	unknown	20:10–21:00 (good, 0.83 h)	72.5° 16:10	8.6	31%	13.3°
2037-03-23 Mon	14	—	unknown	20:15–21:40 (marginal, 1.42 h)	72.5° 16:05	8.55	41%	24.6°
2037-03-24 Tue	11	—	unknown	20:15–21:30 (marginal, 1.25 h)	72.5° 16:00	8.5	52%	37.4°
2037-03-25 Wed	9	—	unknown	20:15–21:25 (marginal, 1.17 h)	72.5° 15:55	8.44	63%	50.8°
2037-03-26 Thu	9	—	unknown	20:15–21:20 (marginal, 1.08 h)	72.5° 15:50	8.39	73%	64.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2037-02-25&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.