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: 01-04 (37), 01-05 (32), 01-15 (31), 01-16 (30), 01-14 (28) — by astronomy; check the weather when the night is within four days.

2036-01-04astronomy score per night — click a bar for that night2036-02-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-01-04 Fri	37	—	unknown	18:45–20:30 (good, 1.75 h)	87.2° 14:25	11.42	32%	60.8°
2036-01-05 Sat	32	—	unknown	18:45–20:20 (good, 1.58 h)	87.2° 14:20	11.41	42%	64.3°
2036-01-06 Sun	27	—	unknown	18:45–20:10 (good, 1.42 h)	87.2° 14:20	11.39	52%	69.1°
2036-01-07 Mon	23	—	unknown	18:50–19:40 (good, 0.83 h)	87.2° 14:15	11.38	62%	75.0°
2036-01-08 Tue	22	—	unknown	18:50–19:15 (good, 0.42 h)	87.2° 14:10	11.36	73%	81.8°
2036-01-09 Wed	21	—	unknown	18:50–19:15 (good, 0.42 h)	87.2° 14:05	11.35	82%	89.2°
2036-01-10 Thu	22	—	unknown	18:50–19:35 (good, 0.75 h)	87.2° 14:05	11.33	90%	96.8°
2036-01-11 Fri	24	—	unknown	18:50–19:50 (good, 1.0 h)	87.2° 14:00	11.31	96%	104.3°
2036-01-12 Sat	25	—	unknown	18:55–19:55 (good, 1.0 h)	87.2° 13:55	11.29	100%	111.1°
2036-01-13 Sun	27	—	unknown	18:55–19:55 (good, 1.0 h)	87.2° 13:50	11.28	100%	116.7°
2036-01-14 Mon	28	—	unknown	18:55–19:55 (good, 1.0 h)	87.2° 13:45	11.26	97%	120.3°
2036-01-15 Tue	31	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:45	11.23	91%	121.7°
2036-01-16 Wed	30	—	unknown	18:55–20:00 (good, 1.08 h)	87.2° 13:40	11.21	83%	120.7°
2036-01-17 Thu	27	—	unknown	19:00–19:55 (good, 0.92 h)	87.2° 13:35	11.19	74%	117.8°
2036-01-18 Fri	26	—	unknown	19:00–19:50 (good, 0.83 h)	87.2° 13:30	11.17	64%	113.3°
2036-01-19 Sat	25	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:25	11.14	54%	107.9°
2036-01-20 Sun	24	—	unknown	19:00–19:45 (good, 0.75 h)	87.2° 13:25	11.12	43%	101.8°
2036-01-21 Mon	23	—	unknown	19:00–19:40 (good, 0.67 h)	87.2° 13:20	11.09	34%	95.5°
2036-01-22 Tue	21	—	unknown	19:05–19:35 (good, 0.5 h)	87.2° 13:15	11.07	25%	89.2°
2036-01-23 Wed	19	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.04	17%	82.9°
2036-01-24 Thu	18	—	unknown	19:05–19:30 (good, 0.42 h)	87.2° 13:10	11.01	11%	76.9°
2036-01-25 Fri	16	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	10.98	6%	71.4°
2036-01-26 Sat	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:00	10.96	2%	66.6°
2036-01-27 Sun	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.93	0%	62.7°
2036-01-28 Mon	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.9	0%	59.9°
2036-01-29 Tue	11	—	unknown	18:40–19:45 (marginal, 1.08 h)	87.2° 12:50	10.87	2%	58.5°
2036-01-30 Wed	10	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.84	6%	58.6°
2036-01-31 Thu	9	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.8	11%	60.3°
2036-02-01 Fri	9	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.77	18%	63.5°
2036-02-02 Sat	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:30	10.74	26%	67.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-01-04&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.