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 Seven Sisters: 02-25 (86), 02-26 (83), 02-27 (81), 02-28 (79), 03-01 (76) — by astronomy; check the weather when the night is within four days.

2030-02-25astronomy score per night — click a bar for that night2030-03-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2030-02-25 Mon	86	—	unknown	19:40–23:00 (good, 3.33 h)	72.5° 17:45	9.82	40%	160.9°
2030-02-26 Tue	83	—	unknown	19:45–22:55 (good, 3.17 h)	72.5° 17:45	9.78	30%	147.1°
2030-02-27 Wed	81	—	unknown	19:45–22:50 (good, 3.08 h)	72.5° 17:40	9.74	20%	133.3°
2030-02-28 Thu	79	—	unknown	19:45–22:45 (good, 3.0 h)	72.5° 17:35	9.69	12%	119.7°
2030-03-01 Fri	76	—	unknown	19:45–22:40 (good, 2.92 h)	72.5° 17:30	9.65	6%	106.3°
2030-03-02 Sat	74	—	unknown	19:45–22:40 (good, 2.92 h)	72.5° 17:25	9.6	2%	93.1°
2030-03-03 Sun	71	—	unknown	19:50–22:35 (good, 2.75 h)	72.5° 17:25	9.55	0%	80.1°
2030-03-04 Mon	69	—	unknown	19:50–22:30 (good, 2.67 h)	72.5° 17:20	9.51	1%	67.3°
2030-03-05 Tue	66	—	unknown	19:50–22:25 (good, 2.58 h)	72.5° 17:15	9.46	3%	54.8°
2030-03-06 Wed	62	—	unknown	19:50–22:20 (good, 2.5 h)	72.5° 17:10	9.41	7%	42.5°
2030-03-07 Thu	54	—	unknown	19:55–22:20 (good, 2.42 h)	72.5° 17:10	9.37	13%	30.4°
2030-03-08 Fri	47	—	unknown	19:55–22:05 (good, 2.17 h)	72.5° 17:05	9.32	20%	18.5°
2030-03-09 Sat	39	—	unknown	19:55–21:55 (good, 2.0 h)	72.5° 17:00	9.27	28%	6.9°
2030-03-10 Sun	31	—	unknown	19:55–21:45 (good, 1.83 h)	72.5° 16:55	9.22	37%	5.8°
2030-03-11 Mon	23	—	unknown	20:00–20:15 (good, 0.25 h)	72.5° 16:50	9.17	46%	17.3°
2030-03-12 Tue	17	—	unknown	20:00–22:15 (marginal, 2.25 h)	72.5° 16:50	9.12	56%	29.3°
2030-03-13 Wed	15	—	unknown	20:00–22:05 (marginal, 2.08 h)	72.5° 16:45	9.07	65%	41.5°
2030-03-14 Thu	14	—	unknown	20:00–22:00 (marginal, 2.0 h)	72.5° 16:40	9.02	74%	54.0°
2030-03-15 Fri	15	—	unknown	20:05–22:00 (marginal, 1.92 h)	72.5° 16:35	8.97	83%	66.9°
2030-03-16 Sat	17	—	unknown	20:05–22:00 (marginal, 1.92 h)	72.5° 16:30	8.92	90%	80.1°
2030-03-17 Sun	21	—	unknown	20:05–20:45 (good, 0.67 h)	72.5° 16:30	8.87	96%	93.8°
2030-03-18 Mon	26	—	unknown	20:05–21:15 (good, 1.17 h)	72.5° 16:25	8.82	99%	108.0°
2030-03-19 Tue	29	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:20	8.77	100%	122.4°
2030-03-20 Wed	29	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:15	8.72	98%	137.0°
2030-03-21 Thu	32	—	unknown	20:10–21:15 (good, 1.08 h)	72.5° 16:15	8.67	93%	151.7°
2030-03-22 Fri	30	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:10	8.62	86%	166.4°
2030-03-23 Sat	28	—	unknown	20:15–21:15 (good, 1.0 h)	72.5° 16:05	8.56	77%	177.3°
2030-03-24 Sun	27	—	unknown	20:15–21:10 (good, 0.92 h)	72.5° 16:00	8.51	66%	164.2°
2030-03-25 Mon	25	—	unknown	20:15–21:10 (good, 0.92 h)	72.5° 15:55	8.46	55%	150.2°
2030-03-26 Tue	23	—	unknown	20:15–21:05 (good, 0.83 h)	72.5° 15:55	8.41	44%	136.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2030-02-25&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.