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: 02-16 (100), 02-17 (100), 02-18 (100), 02-19 (100), 02-20 (97) — by astronomy; check the weather when the night is within four days.

2036-02-16astronomy score per night — click a bar for that night2036-03-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-02-16 Sat	100	—	unknown	19:30–23:30 (good, 4.0 h)	72.5° 18:25	10.22	70%	152.6°
2036-02-17 Sun	100	—	unknown	19:30–23:30 (good, 4.0 h)	72.5° 18:20	10.18	60%	164.0°
2036-02-18 Mon	100	—	unknown	19:35–23:30 (good, 3.92 h)	72.5° 18:15	10.14	50%	170.6°
2036-02-19 Tue	100	—	unknown	19:35–23:25 (good, 3.83 h)	72.5° 18:15	10.1	41%	165.1°
2036-02-20 Wed	97	—	unknown	19:35–23:20 (good, 3.75 h)	72.5° 18:10	10.06	32%	154.7°
2036-02-21 Thu	96	—	unknown	19:35–23:15 (good, 3.67 h)	72.5° 18:05	10.02	23%	143.4°
2036-02-22 Fri	94	—	unknown	19:35–23:10 (good, 3.58 h)	72.5° 18:00	9.97	16%	132.0°
2036-02-23 Sat	91	—	unknown	19:40–23:10 (good, 3.5 h)	72.5° 17:55	9.93	10%	120.4°
2036-02-24 Sun	89	—	unknown	19:40–23:05 (good, 3.42 h)	72.5° 17:55	9.89	5%	108.7°
2036-02-25 Mon	87	—	unknown	19:40–23:00 (good, 3.33 h)	72.5° 17:50	9.84	2%	96.9°
2036-02-26 Tue	86	—	unknown	19:40–22:55 (good, 3.25 h)	72.5° 17:45	9.8	0%	84.9°
2036-02-27 Wed	82	—	unknown	19:45–22:50 (good, 3.08 h)	72.5° 17:40	9.76	0%	72.8°
2036-02-28 Thu	80	—	unknown	19:45–22:50 (good, 3.08 h)	72.5° 17:35	9.71	3%	60.5°
2036-02-29 Fri	74	—	unknown	19:45–22:45 (good, 3.0 h)	72.5° 17:35	9.67	7%	48.1°
2036-03-01 Sat	68	—	unknown	19:45–22:40 (good, 2.92 h)	72.5° 17:30	9.62	14%	35.7°
2036-03-02 Sun	57	—	unknown	19:50–22:35 (good, 2.75 h)	72.5° 17:25	9.57	22%	23.4°
2036-03-03 Mon	46	—	unknown	19:50–22:20 (good, 2.5 h)	72.5° 17:20	9.53	31%	12.5°
2036-03-04 Tue	35	—	unknown	19:50–22:00 (good, 2.17 h)	72.5° 17:20	9.48	42%	10.8°
2036-03-05 Wed	25	—	unknown	19:50–22:45 (marginal, 2.92 h)	72.5° 17:15	9.44	53%	21.2°
2036-03-06 Thu	18	—	unknown	19:55–22:30 (marginal, 2.58 h)	72.5° 17:10	9.39	64%	34.4°
2036-03-07 Fri	17	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.5° 17:05	9.34	75%	48.2°
2036-03-08 Sat	18	—	unknown	19:55–22:20 (marginal, 2.42 h)	72.5° 17:00	9.29	84%	62.5°
2036-03-09 Sun	21	—	unknown	19:55–22:20 (marginal, 2.42 h)	72.5° 17:00	9.24	92%	77.0°
2036-03-10 Mon	27	—	unknown	19:55–20:50 (good, 0.92 h)	72.5° 16:55	9.2	97%	91.6°
2036-03-11 Tue	33	—	unknown	20:00–21:40 (good, 1.67 h)	72.5° 16:50	9.15	100%	106.0°
2036-03-12 Wed	40	—	unknown	20:00–21:45 (good, 1.75 h)	72.5° 16:45	9.1	100%	120.2°
2036-03-13 Thu	40	—	unknown	20:00–21:45 (good, 1.75 h)	72.5° 16:40	9.05	97%	134.1°
2036-03-14 Fri	44	—	unknown	20:00–21:40 (good, 1.67 h)	72.5° 16:40	9.0	92%	147.4°
2036-03-15 Sat	43	—	unknown	20:05–21:45 (good, 1.67 h)	72.5° 16:35	8.95	85%	159.7°
2036-03-16 Sun	41	—	unknown	20:05–21:40 (good, 1.58 h)	72.5° 16:30	8.9	77%	169.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-02-16&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.