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: 03-17 (3), 03-18 (2), 03-19 (1), 03-20 (1), 03-21 (1) — by astronomy; check the weather when the night is within four days.

2029-03-17astronomy score per night — click a bar for that night2029-04-15

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-03-17 Sat	3	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.1° 14:15	8.86	7%	15.6°
2029-03-18 Sun	2	—	unknown	20:05–20:10 (marginal, 0.08 h)	79.1° 14:10	8.81	12%	16.2°
2029-03-19 Mon	1	—	unknown	—	79.1° 14:05	8.76	19%	23.6°
2029-03-20 Tue	1	—	unknown	—	79.1° 14:05	8.71	27%	33.7°
2029-03-21 Wed	1	—	unknown	—	79.1° 14:00	8.66	36%	44.9°
2029-03-22 Thu	0	—	unknown	—	79.1° 13:55	8.6	46%	56.7°
2029-03-23 Fri	0	—	unknown	—	79.1° 13:50	8.55	56%	69.0°
2029-03-24 Sat	0	—	unknown	—	79.1° 13:50	8.5	67%	81.8°
2029-03-25 Sun	0	—	unknown	—	79.1° 14:45	8.45	77%	95.1°
2029-03-26 Mon	0	—	unknown	—	79.1° 14:40	8.39	86%	108.9°
2029-03-27 Tue	0	—	unknown	—	79.1° 14:35	8.34	93%	123.0°
2029-03-28 Wed	0	—	unknown	—	79.1° 14:30	8.28	98%	137.1°
2029-03-29 Thu	0	—	unknown	—	79.1° 14:30	8.23	100%	150.8°
2029-03-30 Fri	0	—	unknown	—	79.1° 14:25	8.18	99%	162.1°
2029-03-31 Sat	0	—	unknown	—	79.1° 14:20	8.12	95%	164.4°
2029-04-01 Sun	0	—	unknown	—	79.1° 14:15	8.07	88%	155.4°
2029-04-02 Mon	0	—	unknown	—	79.1° 14:10	8.01	80%	143.0°
2029-04-03 Tue	0	—	unknown	—	79.1° 14:10	7.96	70%	130.0°
2029-04-04 Wed	0	—	unknown	—	79.1° 14:05	7.9	59%	117.0°
2029-04-05 Thu	0	—	unknown	—	79.1° 14:00	7.85	49%	104.4°
2029-04-06 Fri	0	—	unknown	—	79.1° 13:55	7.79	39%	92.1°
2029-04-07 Sat	0	—	unknown	—	79.1° 13:55	7.73	29%	80.1°
2029-04-08 Sun	0	—	unknown	—	79.1° 13:50	7.68	21%	68.3°
2029-04-09 Mon	0	—	unknown	—	79.1° 13:45	7.62	14%	56.8°
2029-04-10 Tue	0	—	unknown	—	79.1° 13:40	7.56	8%	45.5°
2029-04-11 Wed	0	—	unknown	—	79.1° 13:35	7.51	4%	34.7°
2029-04-12 Thu	0	—	unknown	—	79.1° 13:35	7.45	1%	24.6°
2029-04-13 Fri	0	—	unknown	—	79.1° 13:30	7.39	0%	16.9°
2029-04-14 Sat	0	—	unknown	—	79.1° 13:25	7.33	1%	15.3°
2029-04-15 Sun	0	—	unknown	—	79.1° 13:20	7.28	4%	21.5°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-03-17&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.