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: 03-06 (59), 03-07 (58), 03-08 (58), 03-09 (57), 03-10 (55) — by astronomy; check the weather when the night is within four days.

2034-02-25astronomy score per night — click a bar for that night2034-03-26

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2034-02-25 Sat	33	—	unknown	19:40–20:00 (good, 0.33 h)	72.5° 17:45	9.82	53%	14.1°
2034-02-26 Sun	23	—	unknown	19:45–23:05 (marginal, 3.33 h)	72.5° 17:45	9.78	64%	26.3°
2034-02-27 Mon	19	—	unknown	19:45–22:55 (marginal, 3.17 h)	72.5° 17:40	9.73	74%	39.3°
2034-02-28 Tue	20	—	unknown	19:45–22:50 (marginal, 3.08 h)	72.5° 17:35	9.69	83%	52.4°
2034-03-01 Wed	23	—	unknown	19:45–22:50 (marginal, 3.08 h)	72.5° 17:30	9.64	90%	65.3°
2034-03-02 Thu	29	—	unknown	19:45–20:10 (good, 0.42 h)	72.5° 17:25	9.6	95%	78.1°
2034-03-03 Fri	36	—	unknown	19:50–21:15 (good, 1.42 h)	72.5° 17:25	9.55	99%	90.6°
2034-03-04 Sat	44	—	unknown	19:50–22:05 (good, 2.25 h)	72.5° 17:20	9.51	100%	103.0°
2034-03-05 Sun	51	—	unknown	19:50–22:10 (good, 2.33 h)	72.5° 17:15	9.46	99%	115.2°
2034-03-06 Mon	59	—	unknown	19:50–22:15 (good, 2.42 h)	72.5° 17:10	9.41	97%	127.2°
2034-03-07 Tue	58	—	unknown	19:55–22:10 (good, 2.25 h)	72.5° 17:10	9.36	93%	139.0°
2034-03-08 Wed	58	—	unknown	19:55–22:10 (good, 2.25 h)	72.5° 17:05	9.32	87%	150.5°
2034-03-09 Thu	57	—	unknown	19:55–22:10 (good, 2.25 h)	72.5° 17:00	9.27	80%	161.4°
2034-03-10 Fri	55	—	unknown	19:55–22:05 (good, 2.17 h)	72.5° 16:55	9.22	72%	170.3°
2034-03-11 Sat	52	—	unknown	20:00–22:05 (good, 2.08 h)	72.5° 16:50	9.17	63%	168.9°
2034-03-12 Sun	50	—	unknown	20:00–22:00 (good, 2.0 h)	72.5° 16:50	9.12	53%	159.1°
2034-03-13 Mon	48	—	unknown	20:00–21:55 (good, 1.92 h)	72.5° 16:45	9.07	44%	147.5°
2034-03-14 Tue	47	—	unknown	20:00–21:50 (good, 1.83 h)	72.5° 16:40	9.02	34%	135.4°
2034-03-15 Wed	43	—	unknown	20:05–21:45 (good, 1.67 h)	72.5° 16:35	8.97	24%	122.6°
2034-03-16 Thu	42	—	unknown	20:05–21:45 (good, 1.67 h)	72.5° 16:30	8.92	16%	109.4°
2034-03-17 Fri	40	—	unknown	20:05–21:40 (good, 1.58 h)	72.5° 16:30	8.87	8%	95.7°
2034-03-18 Sat	38	—	unknown	20:05–21:35 (good, 1.5 h)	72.5° 16:25	8.82	3%	81.6°
2034-03-19 Sun	36	—	unknown	20:10–21:30 (good, 1.33 h)	72.5° 16:20	8.77	0%	67.1°
2034-03-20 Mon	34	—	unknown	20:10–21:30 (good, 1.33 h)	72.5° 16:15	8.72	0%	52.4°
2034-03-21 Tue	32	—	unknown	20:10–21:25 (good, 1.25 h)	72.5° 16:15	8.67	3%	37.8°
2034-03-22 Wed	28	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:10	8.61	9%	23.5°
2034-03-23 Thu	23	—	unknown	20:15–21:10 (good, 0.92 h)	72.5° 16:05	8.56	17%	11.1°
2034-03-24 Fri	19	—	unknown	20:15–20:55 (good, 0.67 h)	72.5° 16:00	8.51	27%	11.3°
2034-03-25 Sat	14	—	unknown	20:15–20:40 (good, 0.42 h)	72.5° 15:55	8.46	38%	23.1°
2034-03-26 Sun	10	—	unknown	21:15–22:25 (marginal, 1.17 h)	72.5° 16:55	8.4	49%	36.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2034-02-25&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.