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: 02-22 (41), 02-23 (41), 02-24 (38), 02-21 (37), 02-25 (37) — by astronomy; check the weather when the night is within four days.

2046-02-16astronomy score per night — click a bar for that night2046-03-17

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-02-16 Fri	17	—	unknown	19:30–21:50 (marginal, 2.33 h)	79.2° 16:10	10.2	78%	60.3°
2046-02-17 Sat	19	—	unknown	19:30–21:50 (marginal, 2.33 h)	79.2° 16:05	10.16	87%	74.0°
2046-02-18 Sun	23	—	unknown	19:35–19:55 (good, 0.33 h)	79.2° 16:05	10.12	94%	88.1°
2046-02-19 Mon	29	—	unknown	19:35–21:05 (good, 1.5 h)	79.2° 16:00	10.08	98%	102.7°
2046-02-20 Tue	36	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:55	10.03	100%	117.4°
2046-02-21 Wed	37	—	unknown	19:35–21:15 (good, 1.67 h)	79.2° 15:50	9.99	98%	132.0°
2046-02-22 Thu	41	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:45	9.95	94%	146.0°
2046-02-23 Fri	41	—	unknown	19:40–21:15 (good, 1.58 h)	79.2° 15:45	9.91	87%	158.5°
2046-02-24 Sat	38	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:40	9.86	78%	165.7°
2046-02-25 Sun	37	—	unknown	19:40–21:10 (good, 1.5 h)	79.2° 15:35	9.82	68%	161.4°
2046-02-26 Mon	35	—	unknown	19:45–21:05 (good, 1.33 h)	79.2° 15:30	9.77	58%	150.8°
2046-02-27 Tue	33	—	unknown	19:45–21:00 (good, 1.25 h)	79.2° 15:25	9.73	47%	138.9°
2046-02-28 Wed	31	—	unknown	19:45–20:55 (good, 1.17 h)	79.2° 15:25	9.69	37%	126.9°
2046-03-01 Thu	29	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:20	9.64	28%	114.9°
2046-03-02 Fri	28	—	unknown	19:45–20:50 (good, 1.08 h)	79.2° 15:15	9.59	20%	103.1°
2046-03-03 Sat	26	—	unknown	19:50–20:45 (good, 0.92 h)	79.2° 15:10	9.55	12%	91.4°
2046-03-04 Sun	24	—	unknown	19:50–20:40 (good, 0.83 h)	79.2° 15:10	9.5	7%	79.8°
2046-03-05 Mon	23	—	unknown	19:50–20:35 (good, 0.75 h)	79.2° 15:05	9.45	3%	68.3°
2046-03-06 Tue	21	—	unknown	19:50–20:30 (good, 0.67 h)	79.2° 15:00	9.41	1%	57.0°
2046-03-07 Wed	19	—	unknown	19:55–20:30 (good, 0.58 h)	79.2° 14:55	9.36	0%	45.8°
2046-03-08 Thu	18	—	unknown	19:55–20:25 (good, 0.5 h)	79.2° 14:50	9.31	1%	34.8°
2046-03-09 Fri	15	—	unknown	19:55–20:20 (good, 0.42 h)	79.2° 14:50	9.26	4%	24.6°
2046-03-10 Sat	13	—	unknown	19:55–20:15 (good, 0.33 h)	79.2° 14:45	9.22	9%	16.4°
2046-03-11 Sun	9	—	unknown	20:00–20:05 (good, 0.08 h)	79.2° 14:40	9.17	15%	14.8°
2046-03-12 Mon	7	—	unknown	20:00–20:40 (marginal, 0.67 h)	79.2° 14:35	9.12	23%	21.4°
2046-03-13 Tue	5	—	unknown	20:00–20:35 (marginal, 0.58 h)	79.2° 14:30	9.07	32%	31.7°
2046-03-14 Wed	4	—	unknown	20:00–20:30 (marginal, 0.5 h)	79.2° 14:30	9.02	42%	43.4°
2046-03-15 Thu	3	—	unknown	20:05–20:20 (marginal, 0.25 h)	79.2° 14:25	8.97	52%	55.8°
2046-03-16 Fri	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:20	8.92	63%	68.8°
2046-03-17 Sat	2	—	unknown	20:05–20:15 (marginal, 0.17 h)	79.2° 14:15	8.87	74%	82.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-02-16&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.