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: 06-05 (2), 06-06 (2), 06-07 (2), 06-08 (2), 06-01 (1) — by astronomy; check the weather when the night is within four days.

2043-05-10astronomy score per night — click a bar for that night2043-06-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-05-10 Sun	0	—	unknown	—	79.2° 11:40	5.86	5%	43.8°
2043-05-11 Mon	0	—	unknown	—	79.2° 11:35	5.8	12%	57.4°
2043-05-12 Tue	0	—	unknown	—	79.2° 11:35	5.75	20%	71.1°
2043-05-13 Wed	0	—	unknown	—	79.2° 11:30	5.69	30%	84.4°
2043-05-14 Thu	0	—	unknown	—	79.2° 11:25	5.64	40%	97.3°
2043-05-15 Fri	0	—	unknown	—	79.2° 11:20	5.58	50%	109.7°
2043-05-16 Sat	0	—	unknown	—	79.2° 11:20	5.53	61%	121.7°
2043-05-17 Sun	0	—	unknown	—	79.2° 11:15	5.48	70%	133.3°
2043-05-18 Mon	0	—	unknown	—	79.2° 11:10	5.43	79%	144.1°
2043-05-19 Tue	0	—	unknown	—	79.2° 11:05	5.38	86%	153.9°
2043-05-20 Wed	0	—	unknown	—	79.2° 11:00	5.33	92%	161.1°
2043-05-21 Thu	0	—	unknown	—	79.2° 11:00	5.28	96%	162.5°
2043-05-22 Fri	0	—	unknown	—	79.2° 10:55	5.23	99%	157.0°
2043-05-23 Sat	0	—	unknown	—	79.2° 10:50	5.18	100%	148.0°
2043-05-24 Sun	0	—	unknown	—	79.2° 10:45	5.13	99%	137.7°
2043-05-25 Mon	0	—	unknown	—	79.2° 10:40	5.09	96%	126.7°
2043-05-26 Tue	0	—	unknown	—	79.2° 10:40	5.04	92%	115.3°
2043-05-27 Wed	0	—	unknown	—	79.2° 10:35	5.0	86%	103.7°
2043-05-28 Thu	0	—	unknown	—	79.2° 10:30	4.96	78%	91.8°
2043-05-29 Fri	0	—	unknown	—	79.2° 10:25	4.92	69%	79.7°
2043-05-30 Sat	0	—	unknown	—	79.2° 10:25	4.88	59%	67.3°
2043-05-31 Sun	0	—	unknown	—	79.2° 10:20	4.84	49%	54.8°
2043-06-01 Mon	1	—	unknown	—	79.2° 10:15	4.8	38%	42.3°
2043-06-02 Tue	1	—	unknown	—	79.2° 10:10	4.76	27%	30.1°
2043-06-03 Wed	1	—	unknown	—	79.2° 10:05	4.73	17%	20.0°
2043-06-04 Thu	1	—	unknown	—	79.2° 10:05	4.7	9%	17.5°
2043-06-05 Fri	2	—	unknown	04:30–04:35 (marginal, 0.08 h)	79.2° 10:00	4.67	4%	25.4°
2043-06-06 Sat	2	—	unknown	04:30–04:35 (marginal, 0.08 h)	79.2° 09:55	4.64	1%	37.8°
2043-06-07 Sun	2	—	unknown	04:25–04:30 (marginal, 0.08 h)	79.2° 09:50	4.61	0%	51.4°
2043-06-08 Mon	2	—	unknown	04:20–04:30 (marginal, 0.17 h)	79.2° 09:45	4.58	4%	65.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-05-10&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.