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: 01-18 (100), 01-19 (100), 01-20 (100), 01-21 (100), 01-22 (100) — by astronomy; check the weather when the night is within four days.

2042-01-18astronomy score per night — click a bar for that night2042-02-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2042-01-18 Sat	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:05	11.15	11%	131.2°
2042-01-19 Sun	100	—	unknown	19:00–23:35 (good, 4.58 h)	79.2° 18:00	11.13	5%	118.6°
2042-01-20 Mon	100	—	unknown	19:00–23:30 (good, 4.5 h)	79.2° 17:55	11.1	1%	105.4°
2042-01-21 Tue	100	—	unknown	19:00–23:25 (good, 4.42 h)	79.2° 17:55	11.08	0%	91.8°
2042-01-22 Wed	100	—	unknown	19:05–23:20 (good, 4.25 h)	79.2° 17:50	11.05	2%	78.0°
2042-01-23 Thu	100	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:45	11.03	6%	64.1°
2042-01-24 Fri	95	—	unknown	19:05–23:15 (good, 4.17 h)	79.2° 17:40	11.0	13%	50.5°
2042-01-25 Sat	87	—	unknown	19:05–23:10 (good, 4.08 h)	79.2° 17:35	10.97	22%	37.6°
2042-01-26 Sun	68	—	unknown	19:10–22:50 (good, 3.67 h)	79.2° 17:35	10.94	32%	26.4°
2042-01-27 Mon	52	—	unknown	19:10–22:35 (good, 3.42 h)	79.2° 17:30	10.91	43%	19.6°
2042-01-28 Tue	37	—	unknown	19:10–23:20 (marginal, 4.17 h)	79.2° 17:25	10.88	55%	21.2°
2042-01-29 Wed	25	—	unknown	19:10–23:05 (marginal, 3.92 h)	79.2° 17:20	10.85	65%	29.5°
2042-01-30 Thu	22	—	unknown	19:10–22:50 (marginal, 3.67 h)	79.2° 17:15	10.82	75%	40.3°
2042-01-31 Fri	22	—	unknown	19:15–22:45 (marginal, 3.5 h)	79.2° 17:15	10.79	83%	51.9°
2042-02-01 Sat	26	—	unknown	19:15–22:45 (marginal, 3.5 h)	79.2° 17:10	10.75	90%	63.8°
2042-02-02 Sun	32	—	unknown	19:15–19:35 (good, 0.33 h)	79.2° 17:05	10.72	95%	75.7°
2042-02-03 Mon	41	—	unknown	19:15–20:40 (good, 1.42 h)	79.2° 17:00	10.69	98%	87.5°
2042-02-04 Tue	50	—	unknown	19:20–21:45 (good, 2.42 h)	79.2° 17:00	10.65	100%	99.1°
2042-02-05 Wed	59	—	unknown	19:20–22:05 (good, 2.75 h)	79.2° 16:55	10.62	99%	110.5°
2042-02-06 Thu	66	—	unknown	19:20–22:10 (good, 2.83 h)	79.2° 16:50	10.58	97%	121.7°
2042-02-07 Fri	72	—	unknown	19:20–22:10 (good, 2.83 h)	79.2° 16:45	10.55	93%	132.6°
2042-02-08 Sat	73	—	unknown	19:20–22:05 (good, 2.75 h)	79.2° 16:40	10.51	87%	142.9°
2042-02-09 Sun	71	—	unknown	19:25–22:10 (good, 2.75 h)	79.2° 16:40	10.47	80%	152.3°
2042-02-10 Mon	69	—	unknown	19:25–22:05 (good, 2.67 h)	79.2° 16:35	10.44	72%	159.2°
2042-02-11 Tue	67	—	unknown	19:25–22:05 (good, 2.67 h)	79.2° 16:30	10.4	63%	160.8°
2042-02-12 Wed	65	—	unknown	19:25–22:00 (good, 2.58 h)	79.2° 16:25	10.36	54%	155.8°
2042-02-13 Thu	62	—	unknown	19:30–21:55 (good, 2.42 h)	79.2° 16:20	10.32	44%	146.8°
2042-02-14 Fri	60	—	unknown	19:30–21:50 (good, 2.33 h)	79.2° 16:20	10.28	34%	136.0°
2042-02-15 Sat	57	—	unknown	19:30–21:45 (good, 2.25 h)	79.2° 16:15	10.24	24%	124.0°
2042-02-16 Sun	55	—	unknown	19:30–21:45 (good, 2.25 h)	79.2° 16:10	10.2	15%	111.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2042-01-18&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.