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 North America Nebula: 12-19 (82), 12-20 (76), 12-21 (70), 12-22 (63), 12-23 (54) — by astronomy; check the weather when the night is within four days.

2036-12-19astronomy score per night — click a bar for that night2037-01-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-12-19 Fri	82	—	unknown	18:35–21:45 (good, 3.17 h)	87.2° 15:25	11.51	5%	66.5°
2036-12-20 Sat	76	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	10%	63.0°
2036-12-21 Sun	70	—	unknown	18:35–21:40 (good, 3.08 h)	87.2° 15:20	11.51	16%	60.8°
2036-12-22 Mon	63	—	unknown	18:35–21:35 (good, 3.0 h)	87.2° 15:15	11.51	24%	59.9°
2036-12-23 Tue	54	—	unknown	18:40–21:20 (good, 2.67 h)	87.2° 15:10	11.5	32%	60.4°
2036-12-24 Wed	47	—	unknown	18:40–21:05 (good, 2.42 h)	87.2° 15:05	11.5	42%	62.3°
2036-12-25 Thu	41	—	unknown	18:40–20:55 (good, 2.25 h)	87.2° 15:05	11.5	51%	65.5°
2036-12-26 Fri	35	—	unknown	18:40–20:25 (good, 1.75 h)	87.2° 15:00	11.49	61%	69.8°
2036-12-27 Sat	32	—	unknown	18:40–19:45 (good, 1.08 h)	87.2° 14:55	11.49	70%	75.0°
2036-12-28 Sun	30	—	unknown	18:40–19:25 (good, 0.75 h)	87.2° 14:50	11.48	79%	81.0°
2036-12-29 Mon	30	—	unknown	18:40–19:30 (good, 0.83 h)	87.2° 14:45	11.47	87%	87.5°
2036-12-30 Tue	32	—	unknown	18:40–19:55 (good, 1.25 h)	87.2° 14:45	11.47	94%	94.4°
2036-12-31 Wed	34	—	unknown	18:45–20:25 (good, 1.67 h)	87.2° 14:40	11.46	98%	101.3°
2037-01-01 Thu	37	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:35	11.45	100%	107.8°
2037-01-02 Fri	40	—	unknown	18:45–20:35 (good, 1.83 h)	87.2° 14:30	11.44	99%	113.4°
2037-01-03 Sat	47	—	unknown	18:45–20:35 (good, 1.83 h)	87.2° 14:25	11.42	95%	117.5°
2037-01-04 Sun	48	—	unknown	18:45–20:35 (good, 1.83 h)	87.2° 14:25	11.41	89%	119.8°
2037-01-05 Mon	47	—	unknown	18:45–20:40 (good, 1.92 h)	87.2° 14:20	11.4	80%	119.8°
2037-01-06 Tue	44	—	unknown	18:50–20:35 (good, 1.75 h)	87.2° 14:15	11.38	70%	117.8°
2037-01-07 Wed	43	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.37	59%	114.1°
2037-01-08 Thu	42	—	unknown	18:50–20:30 (good, 1.67 h)	87.2° 14:10	11.35	48%	109.0°
2037-01-09 Fri	40	—	unknown	18:50–20:25 (good, 1.58 h)	87.2° 14:05	11.34	37%	103.2°
2037-01-10 Sat	38	—	unknown	18:50–20:20 (good, 1.5 h)	87.2° 14:00	11.32	27%	96.9°
2037-01-11 Sun	36	—	unknown	18:55–20:15 (good, 1.33 h)	87.2° 13:55	11.3	19%	90.4°
2037-01-12 Mon	34	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.28	11%	84.0°
2037-01-13 Tue	33	—	unknown	18:55–20:10 (good, 1.25 h)	87.2° 13:50	11.26	6%	78.0°
2037-01-14 Wed	32	—	unknown	18:55–20:05 (good, 1.17 h)	87.2° 13:45	11.24	2%	72.5°
2037-01-15 Thu	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.22	0%	67.7°
2037-01-16 Fri	29	—	unknown	18:55–19:55 (good, 1.0 h)	87.2° 13:35	11.2	0%	63.9°
2037-01-17 Sat	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.17	2%	61.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-12-19&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.