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: 03-12 (47), 03-13 (47), 03-14 (45), 03-11 (42), 03-15 (42) — by astronomy; check the weather when the night is within four days.

2028-03-04astronomy score per night — click a bar for that night2028-04-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-03-04 Sat	22	—	unknown	19:50–22:45 (marginal, 2.92 h)	72.5° 17:15	9.48	56%	22.0°
2028-03-05 Sun	17	—	unknown	19:50–22:30 (marginal, 2.67 h)	72.5° 17:15	9.44	67%	35.7°
2028-03-06 Mon	16	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.5° 17:10	9.39	77%	49.9°
2028-03-07 Tue	18	—	unknown	19:55–22:25 (marginal, 2.5 h)	72.5° 17:05	9.34	86%	64.5°
2028-03-08 Wed	23	—	unknown	19:20–22:25 (marginal, 3.08 h)	72.5° 17:00	9.29	93%	79.4°
2028-03-09 Thu	30	—	unknown	19:55–21:10 (good, 1.25 h)	72.5° 17:00	9.25	98%	94.6°
2028-03-10 Fri	37	—	unknown	19:55–21:45 (good, 1.83 h)	72.5° 16:55	9.2	100%	109.8°
2028-03-11 Sat	42	—	unknown	20:00–21:50 (good, 1.83 h)	72.5° 16:50	9.15	99%	124.9°
2028-03-12 Sun	47	—	unknown	20:00–21:50 (good, 1.83 h)	72.5° 16:45	9.1	95%	139.8°
2028-03-13 Mon	47	—	unknown	20:00–21:55 (good, 1.92 h)	72.5° 16:40	9.05	88%	154.3°
2028-03-14 Tue	45	—	unknown	20:00–21:50 (good, 1.83 h)	72.5° 16:40	9.0	80%	168.3°
2028-03-15 Wed	42	—	unknown	20:05–21:45 (good, 1.67 h)	72.5° 16:35	8.95	70%	178.1°
2028-03-16 Thu	41	—	unknown	20:05–21:40 (good, 1.58 h)	72.5° 16:30	8.9	60%	165.0°
2028-03-17 Fri	39	—	unknown	20:05–21:35 (good, 1.5 h)	72.5° 16:25	8.85	50%	152.4°
2028-03-18 Sat	37	—	unknown	20:05–21:35 (good, 1.5 h)	72.5° 16:20	8.8	41%	140.0°
2028-03-19 Sun	34	—	unknown	20:10–21:30 (good, 1.33 h)	72.5° 16:20	8.75	31%	127.9°
2028-03-20 Mon	33	—	unknown	20:10–21:25 (good, 1.25 h)	72.5° 16:15	8.7	23%	116.0°
2028-03-21 Tue	31	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:10	8.64	16%	104.1°
2028-03-22 Wed	30	—	unknown	20:10–21:20 (good, 1.17 h)	72.5° 16:05	8.59	9%	92.3°
2028-03-23 Thu	27	—	unknown	20:15–21:15 (good, 1.0 h)	72.5° 16:05	8.54	5%	80.5°
2028-03-24 Fri	25	—	unknown	20:15–21:10 (good, 0.92 h)	72.5° 16:00	8.49	2%	68.6°
2028-03-25 Sat	25	—	unknown	20:15–21:05 (good, 0.83 h)	72.5° 15:55	8.43	0%	56.6°
2028-03-26 Sun	23	—	unknown	21:15–22:00 (good, 0.75 h)	72.5° 16:50	8.38	1%	44.5°
2028-03-27 Mon	20	—	unknown	21:20–22:00 (good, 0.67 h)	72.5° 16:45	8.33	3%	32.3°
2028-03-28 Tue	18	—	unknown	21:20–21:50 (good, 0.5 h)	72.5° 16:45	8.27	7%	19.8°
2028-03-29 Wed	15	—	unknown	21:20–21:45 (good, 0.42 h)	72.5° 16:40	8.22	13%	7.2°
2028-03-30 Thu	11	—	unknown	21:25–21:35 (good, 0.17 h)	72.5° 16:35	8.16	21%	5.6°
2028-03-31 Fri	8	—	unknown	21:25–22:10 (marginal, 0.75 h)	72.5° 16:30	8.11	30%	18.7°
2028-04-01 Sat	6	—	unknown	21:25–22:05 (marginal, 0.67 h)	72.5° 16:25	8.05	40%	32.0°
2028-04-02 Sun	4	—	unknown	21:25–21:55 (marginal, 0.5 h)	72.5° 16:25	8.0	51%	45.6°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-03-04&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.