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: 02-15 (100), 02-16 (100), 02-17 (100), 02-18 (100), 02-19 (100) — by astronomy; check the weather when the night is within four days.

2044-02-13astronomy score per night — click a bar for that night2044-03-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2044-02-13 Sat	66	—	unknown	19:25–22:40 (good, 3.25 h)	72.6° 18:35	10.34	99%	93.6°
2044-02-14 Sun	82	—	unknown	19:30–23:25 (good, 3.92 h)	72.5° 18:35	10.3	96%	107.5°
2044-02-15 Mon	100	—	unknown	19:30–23:30 (good, 4.0 h)	72.6° 18:30	10.26	92%	121.0°
2044-02-16 Tue	100	—	unknown	19:30–23:30 (good, 4.0 h)	72.6° 18:25	10.22	85%	134.1°
2044-02-17 Wed	100	—	unknown	19:30–23:25 (good, 3.92 h)	72.6° 18:20	10.18	77%	146.8°
2044-02-18 Thu	100	—	unknown	19:35–23:30 (good, 3.92 h)	72.6° 18:15	10.14	68%	159.2°
2044-02-19 Fri	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.5° 18:15	10.1	59%	171.3°
2044-02-20 Sat	97	—	unknown	19:35–23:20 (good, 3.75 h)	72.6° 18:10	10.06	49%	176.7°
2044-02-21 Sun	96	—	unknown	19:35–23:15 (good, 3.67 h)	72.6° 18:05	10.01	40%	164.9°
2044-02-22 Mon	93	—	unknown	19:40–23:10 (good, 3.5 h)	72.6° 18:00	9.97	31%	153.1°
2044-02-23 Tue	91	—	unknown	19:40–23:10 (good, 3.5 h)	72.5° 17:55	9.93	22%	141.2°
2044-02-24 Wed	89	—	unknown	19:40–23:05 (good, 3.42 h)	72.6° 17:55	9.89	15%	129.2°
2044-02-25 Thu	88	—	unknown	19:40–23:00 (good, 3.33 h)	72.6° 17:50	9.84	9%	117.0°
2044-02-26 Fri	86	—	unknown	19:40–22:55 (good, 3.25 h)	72.6° 17:45	9.8	4%	104.5°
2044-02-27 Sat	82	—	unknown	19:45–22:50 (good, 3.08 h)	72.6° 17:40	9.75	1%	91.7°
2044-02-28 Sun	80	—	unknown	19:45–22:50 (good, 3.08 h)	72.5° 17:40	9.71	0%	78.7°
2044-02-29 Mon	77	—	unknown	19:45–22:45 (good, 3.0 h)	72.6° 17:35	9.66	1%	65.4°
2044-03-01 Tue	74	—	unknown	19:45–22:40 (good, 2.92 h)	72.6° 17:30	9.62	5%	51.9°
2044-03-02 Wed	67	—	unknown	19:50–22:35 (good, 2.75 h)	72.6° 17:25	9.57	11%	38.2°
2044-03-03 Thu	57	—	unknown	19:50–22:25 (good, 2.58 h)	72.6° 17:20	9.53	19%	24.3°
2044-03-04 Fri	45	—	unknown	19:50–22:15 (good, 2.42 h)	72.5° 17:20	9.48	28%	10.3°
2044-03-05 Sat	35	—	unknown	19:50–22:00 (good, 2.17 h)	72.6° 17:15	9.43	39%	3.8°
2044-03-06 Sun	24	—	unknown	19:55–22:45 (marginal, 2.83 h)	72.6° 17:10	9.38	51%	17.9°
2044-03-07 Mon	17	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.6° 17:05	9.34	62%	32.0°
2044-03-08 Tue	15	—	unknown	19:55–22:20 (marginal, 2.42 h)	72.5° 17:00	9.29	73%	46.2°
2044-03-09 Wed	16	—	unknown	19:55–22:15 (marginal, 2.33 h)	72.6° 17:00	9.24	82%	60.3°
2044-03-10 Thu	19	—	unknown	19:55–22:15 (marginal, 2.33 h)	72.6° 16:55	9.19	90%	74.4°
2044-03-11 Fri	24	—	unknown	20:00–20:30 (good, 0.5 h)	72.6° 16:50	9.14	96%	88.4°
2044-03-12 Sat	30	—	unknown	20:00–21:30 (good, 1.5 h)	72.6° 16:45	9.09	99%	102.1°
2044-03-13 Sun	36	—	unknown	20:00–21:40 (good, 1.67 h)	72.5° 16:45	9.04	100%	115.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2044-02-13&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.