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: 10-13 (100), 10-14 (100), 10-15 (100), 10-16 (100), 10-17 (100) — by astronomy; check the weather when the night is within four days.

2028-10-07astronomy score per night — click a bar for that night2028-11-05

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2028-10-07 Sat	29	—	unknown	22:50–05:55 (marginal, 7.08 h)	72.5° 04:00	9.49	84%	2.9°
2028-10-08 Sun	41	—	unknown	22:35–05:55 (marginal, 7.33 h)	72.5° 03:55	9.53	76%	15.4°
2028-10-09 Mon	57	—	unknown	22:20–06:00 (marginal, 7.67 h)	72.5° 03:55	9.58	66%	28.2°
2028-10-10 Tue	81	—	unknown	22:45–06:00 (good, 7.25 h)	72.5° 03:50	9.62	56%	41.4°
2028-10-11 Wed	90	—	unknown	22:40–06:00 (good, 7.33 h)	72.5° 03:45	9.67	45%	54.8°
2028-10-12 Thu	99	—	unknown	22:35–06:00 (good, 7.42 h)	72.5° 03:40	9.71	34%	68.7°
2028-10-13 Fri	100	—	unknown	22:30–06:05 (good, 7.58 h)	72.5° 03:35	9.76	24%	82.9°
2028-10-14 Sat	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:35	9.8	15%	97.5°
2028-10-15 Sun	100	—	unknown	22:25–06:05 (good, 7.67 h)	72.5° 03:30	9.84	7%	112.4°
2028-10-16 Mon	100	—	unknown	22:20–06:05 (good, 7.75 h)	72.5° 03:25	9.89	2%	127.5°
2028-10-17 Tue	100	—	unknown	22:15–06:05 (good, 7.83 h)	72.5° 03:20	9.93	0%	142.5°
2028-10-18 Wed	100	—	unknown	22:10–06:10 (good, 8.0 h)	72.5° 03:15	9.97	1%	157.5°
2028-10-19 Thu	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:15	10.01	5%	172.2°
2028-10-20 Fri	100	—	unknown	22:05–06:10 (good, 8.08 h)	72.5° 03:10	10.06	11%	173.5°
2028-10-21 Sat	100	—	unknown	22:00–06:10 (good, 8.17 h)	72.5° 03:05	10.1	19%	159.6°
2028-10-22 Sun	100	—	unknown	21:55–06:10 (good, 8.25 h)	72.5° 03:00	10.14	28%	146.2°
2028-10-23 Mon	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 02:55	10.18	37%	133.3°
2028-10-24 Tue	100	—	unknown	21:50–06:15 (good, 8.42 h)	72.5° 02:55	10.22	47%	120.8°
2028-10-25 Wed	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 02:50	10.26	57%	108.5°
2028-10-26 Thu	100	—	unknown	21:55–06:15 (good, 8.33 h)	72.5° 02:45	10.3	66%	96.5°
2028-10-27 Fri	100	—	unknown	22:05–06:20 (good, 8.25 h)	72.5° 02:40	10.33	75%	84.6°
2028-10-28 Sat	100	—	unknown	23:25–05:20 (good, 6.92 h)	72.5° 02:40	10.37	82%	72.8°
2028-10-29 Sun	97	—	unknown	00:40–05:20 (good, 4.67 h)	72.5° 01:35	10.41	89%	61.0°
2028-10-30 Mon	89	—	unknown	03:25–05:20 (good, 1.92 h)	72.5° 01:30	10.45	94%	49.1°
2028-10-31 Tue	46	—	unknown	22:55–05:20 (marginal, 6.42 h)	72.5° 01:25	10.48	98%	37.1°
2028-11-01 Wed	30	—	unknown	02:15–05:25 (marginal, 3.17 h)	72.5° 01:20	10.52	100%	25.0°
2028-11-02 Thu	24	—	unknown	03:20–05:25 (marginal, 2.08 h)	72.5° 01:20	10.56	100%	12.7°
2028-11-03 Fri	23	—	unknown	20:25–21:55 (marginal, 1.5 h)	72.5° 01:15	10.59	98%	0.5°
2028-11-04 Sat	31	—	unknown	20:00–00:10 (marginal, 4.17 h)	72.5° 01:10	10.63	94%	12.5°
2028-11-05 Sun	43	—	unknown	19:45–04:00 (marginal, 8.25 h)	72.5° 01:05	10.66	88%	25.3°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2028-10-07&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.