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: 02-18 (100), 02-19 (100), 02-20 (97), 02-21 (96), 02-22 (93) — by astronomy; check the weather when the night is within four days.

2047-02-18astronomy score per night — click a bar for that night2047-03-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2047-02-18 Mon	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.6° 18:15	10.13	32%	158.5°
2047-02-19 Tue	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.6° 18:10	10.09	22%	145.1°
2047-02-20 Wed	97	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:10	10.04	14%	132.0°
2047-02-21 Thu	96	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:05	10.0	8%	119.0°
2047-02-22 Fri	93	—	unknown	19:40–23:10 (good, 3.5 h)	72.6° 18:00	9.96	3%	106.3°
2047-02-23 Sat	91	—	unknown	19:40–23:05 (good, 3.42 h)	72.6° 17:55	9.92	1%	93.7°
2047-02-24 Sun	89	—	unknown	19:40–23:05 (good, 3.42 h)	72.6° 17:50	9.87	0%	81.4°
2047-02-25 Mon	87	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:50	9.83	1%	69.2°
2047-02-26 Tue	84	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 17:45	9.79	4%	57.1°
2047-02-27 Wed	77	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:40	9.74	9%	45.2°
2047-02-28 Thu	68	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:35	9.7	15%	33.4°
2047-03-01 Fri	58	—	unknown	19:45–22:35 (good, 2.83 h)	72.6° 17:35	9.65	23%	21.6°
2047-03-02 Sat	48	—	unknown	19:45–22:25 (good, 2.67 h)	72.6° 17:30	9.61	31%	9.7°
2047-03-03 Sun	37	—	unknown	19:50–22:10 (good, 2.33 h)	72.6° 17:25	9.56	40%	2.2°
2047-03-04 Mon	28	—	unknown	19:15–22:55 (marginal, 3.67 h)	72.6° 17:20	9.51	50%	14.3°
2047-03-05 Tue	20	—	unknown	19:50–22:40 (marginal, 2.83 h)	72.6° 17:15	9.47	60%	26.7°
2047-03-06 Wed	17	—	unknown	19:50–22:30 (marginal, 2.67 h)	72.6° 17:15	9.42	70%	39.5°
2047-03-07 Thu	17	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.6° 17:10	9.37	79%	52.7°
2047-03-08 Fri	19	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.6° 17:05	9.32	87%	66.4°
2047-03-09 Sat	23	—	unknown	19:55–20:00 (good, 0.08 h)	72.6° 17:00	9.28	94%	80.5°
2047-03-10 Sun	30	—	unknown	19:55–21:15 (good, 1.33 h)	72.6° 16:55	9.23	98%	95.1°
2047-03-11 Mon	37	—	unknown	20:00–21:45 (good, 1.75 h)	72.6° 16:55	9.18	100%	109.9°
2047-03-12 Tue	42	—	unknown	20:00–21:50 (good, 1.83 h)	72.6° 16:50	9.13	99%	125.0°
2047-03-13 Wed	46	—	unknown	20:00–21:50 (good, 1.83 h)	72.6° 16:45	9.08	95%	140.1°
2047-03-14 Thu	47	—	unknown	20:00–21:55 (good, 1.92 h)	72.6° 16:40	9.03	88%	155.0°
2047-03-15 Fri	44	—	unknown	20:05–21:50 (good, 1.75 h)	72.6° 16:40	8.98	79%	169.8°
2047-03-16 Sat	42	—	unknown	20:05–21:45 (good, 1.67 h)	72.6° 16:35	8.93	69%	175.9°
2047-03-17 Sun	41	—	unknown	20:05–21:40 (good, 1.58 h)	72.6° 16:30	8.88	58%	161.8°
2047-03-18 Mon	39	—	unknown	20:05–21:35 (good, 1.5 h)	72.6° 16:25	8.83	47%	148.2°
2047-03-19 Tue	36	—	unknown	20:10–21:35 (good, 1.42 h)	72.6° 16:20	8.78	37%	135.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2047-02-18&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.