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 Triangulum Pinwheel: 03-15 (5), 03-16 (4), 03-17 (3), 03-18 (3), 03-19 (2) — by astronomy; check the weather when the night is within four days.

2036-03-15astronomy score per night — click a bar for that night2036-04-13

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-03-15 Sat	5	—	unknown	20:05–20:25 (marginal, 0.33 h)	79.1° 14:20	8.95	85%	154.2°
2036-03-16 Sun	4	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.1° 14:20	8.9	77%	147.6°
2036-03-17 Mon	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.85	68%	138.5°
2036-03-18 Tue	3	—	unknown	19:35–19:45 (marginal, 0.17 h)	79.2° 14:10	8.8	58%	128.4°
2036-03-19 Wed	2	—	unknown	19:35–19:40 (marginal, 0.08 h)	79.1° 14:05	8.74	48%	117.9°
2036-03-20 Thu	1	—	unknown	—	79.1° 14:05	8.69	39%	107.3°
2036-03-21 Fri	1	—	unknown	—	79.1° 14:00	8.64	30%	96.6°
2036-03-22 Sat	1	—	unknown	—	79.2° 13:55	8.59	22%	85.7°
2036-03-23 Sun	1	—	unknown	—	79.2° 13:50	8.54	14%	74.9°
2036-03-24 Mon	0	—	unknown	—	79.1° 13:45	8.48	8%	64.0°
2036-03-25 Tue	0	—	unknown	—	79.1° 13:45	8.43	4%	53.3°
2036-03-26 Wed	0	—	unknown	—	79.1° 13:40	8.38	1%	42.8°
2036-03-27 Thu	0	—	unknown	—	79.2° 13:35	8.32	0%	33.4°
2036-03-28 Fri	0	—	unknown	—	79.1° 13:30	8.27	1%	26.3°
2036-03-29 Sat	0	—	unknown	—	79.1° 13:25	8.21	5%	24.2°
2036-03-30 Sun	0	—	unknown	—	79.1° 14:25	8.16	10%	28.6°
2036-03-31 Mon	0	—	unknown	—	79.2° 14:20	8.11	18%	37.4°
2036-04-01 Tue	0	—	unknown	—	79.2° 14:15	8.05	27%	48.4°
2036-04-02 Wed	0	—	unknown	—	79.1° 14:10	8.0	38%	60.4°
2036-04-03 Thu	0	—	unknown	—	79.1° 14:05	7.94	49%	72.9°
2036-04-04 Fri	0	—	unknown	—	79.1° 14:05	7.88	61%	85.8°
2036-04-05 Sat	0	—	unknown	—	79.2° 14:00	7.83	72%	98.8°
2036-04-06 Sun	0	—	unknown	—	79.2° 13:55	7.77	81%	111.7°
2036-04-07 Mon	0	—	unknown	—	79.1° 13:50	7.72	89%	124.4°
2036-04-08 Tue	0	—	unknown	—	79.1° 13:50	7.66	95%	136.3°
2036-04-09 Wed	0	—	unknown	—	79.1° 13:45	7.6	99%	146.8°
2036-04-10 Thu	0	—	unknown	—	79.2° 13:40	7.55	100%	154.1°
2036-04-11 Fri	0	—	unknown	—	79.2° 13:35	7.49	98%	155.6°
2036-04-12 Sat	0	—	unknown	—	79.1° 13:30	7.43	95%	150.8°
2036-04-13 Sun	0	—	unknown	—	79.1° 13:30	7.38	89%	142.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-03-15&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.