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: 02-17 (98), 02-18 (98), 02-19 (98), 02-16 (97), 02-20 (97) — by astronomy; check the weather when the night is within four days.

2033-02-10astronomy score per night — click a bar for that night2033-03-11

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-02-10 Thu	23	—	unknown	19:25–23:45 (marginal, 4.33 h)	72.6° 18:45	10.43	89%	45.9°
2033-02-11 Fri	30	—	unknown	19:25–23:45 (marginal, 4.33 h)	72.6° 18:40	10.39	95%	58.1°
2033-02-12 Sat	39	—	unknown	19:25–19:55 (good, 0.5 h)	72.6° 18:35	10.35	98%	70.2°
2033-02-13 Sun	51	—	unknown	19:30–21:30 (good, 2.0 h)	72.6° 18:35	10.31	100%	82.2°
2033-02-14 Mon	65	—	unknown	19:30–22:40 (good, 3.17 h)	72.6° 18:30	10.27	100%	94.1°
2033-02-15 Tue	78	—	unknown	19:30–23:15 (good, 3.75 h)	72.6° 18:25	10.23	98%	105.9°
2033-02-16 Wed	97	—	unknown	19:30–23:20 (good, 3.83 h)	72.6° 18:20	10.19	94%	117.6°
2033-02-17 Thu	98	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:20	10.15	88%	129.3°
2033-02-18 Fri	98	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:15	10.11	82%	141.0°
2033-02-19 Sat	98	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:10	10.07	74%	152.6°
2033-02-20 Sun	97	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:05	10.03	65%	163.9°
2033-02-21 Mon	95	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:00	9.99	56%	172.4°
2033-02-22 Tue	92	—	unknown	19:40–23:10 (good, 3.5 h)	72.6° 18:00	9.94	46%	167.2°
2033-02-23 Wed	91	—	unknown	19:40–23:05 (good, 3.42 h)	72.6° 17:55	9.9	35%	155.4°
2033-02-24 Thu	88	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:50	9.86	25%	142.4°
2033-02-25 Fri	86	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 17:45	9.81	16%	128.7°
2033-02-26 Sat	83	—	unknown	19:45–22:55 (good, 3.17 h)	72.6° 17:40	9.77	9%	114.4°
2033-02-27 Sun	81	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:40	9.72	3%	99.7°
2033-02-28 Mon	78	—	unknown	19:45–22:45 (good, 3.0 h)	72.6° 17:35	9.68	0%	84.7°
2033-03-01 Tue	76	—	unknown	19:45–22:40 (good, 2.92 h)	72.6° 17:30	9.63	1%	69.6°
2033-03-02 Wed	72	—	unknown	19:50–22:40 (good, 2.83 h)	72.6° 17:25	9.59	4%	54.6°
2033-03-03 Thu	66	—	unknown	19:50–22:35 (good, 2.75 h)	72.6° 17:25	9.54	10%	39.8°
2033-03-04 Fri	56	—	unknown	19:50–22:30 (good, 2.67 h)	72.6° 17:20	9.49	18%	25.5°
2033-03-05 Sat	46	—	unknown	19:50–22:15 (good, 2.42 h)	72.6° 17:15	9.45	28%	12.6°
2033-03-06 Sun	36	—	unknown	19:50–22:00 (good, 2.17 h)	72.6° 17:10	9.4	38%	8.2°
2033-03-07 Mon	26	—	unknown	19:55–20:05 (good, 0.17 h)	72.6° 17:05	9.35	49%	18.4°
2033-03-08 Tue	19	—	unknown	19:55–22:30 (marginal, 2.58 h)	72.6° 17:05	9.31	59%	30.7°
2033-03-09 Wed	17	—	unknown	19:55–22:20 (marginal, 2.42 h)	72.6° 17:00	9.26	69%	43.0°
2033-03-10 Thu	16	—	unknown	19:55–22:15 (marginal, 2.33 h)	72.6° 16:55	9.21	78%	55.2°
2033-03-11 Fri	17	—	unknown	20:00–22:15 (marginal, 2.25 h)	72.6° 16:50	9.16	85%	67.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-02-10&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.