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: 09-03 (100), 09-04 (100), 09-05 (100), 09-06 (100), 09-07 (100) — by astronomy; check the weather when the night is within four days.

2046-09-03astronomy score per night — click a bar for that night2046-10-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2046-09-03 Mon	100	—	unknown	01:10–05:15 (good, 4.08 h)	72.6° 06:15	7.73	15%	146.6°
2046-09-04 Tue	100	—	unknown	01:05–05:15 (good, 4.17 h)	72.6° 06:15	7.79	24%	161.1°
2046-09-05 Wed	100	—	unknown	01:05–05:20 (good, 4.25 h)	72.6° 06:10	7.84	34%	175.3°
2046-09-06 Thu	100	—	unknown	01:00–05:20 (good, 4.33 h)	72.6° 06:05	7.9	45%	170.9°
2046-09-07 Fri	100	—	unknown	00:55–05:20 (good, 4.42 h)	72.6° 06:00	7.95	56%	157.5°
2046-09-08 Sat	100	—	unknown	00:50–05:20 (good, 4.5 h)	72.6° 05:55	8.01	66%	144.5°
2046-09-09 Sun	100	—	unknown	00:55–05:25 (good, 4.5 h)	72.6° 05:55	8.06	75%	131.8°
2046-09-10 Mon	100	—	unknown	00:50–05:25 (good, 4.58 h)	72.6° 05:50	8.11	83%	119.4°
2046-09-11 Tue	100	—	unknown	00:55–05:25 (good, 4.5 h)	72.6° 05:45	8.17	90%	107.1°
2046-09-12 Wed	100	—	unknown	01:00–05:25 (good, 4.42 h)	72.6° 05:40	8.22	95%	95.0°
2046-09-13 Thu	70	—	unknown	02:10–05:30 (good, 3.33 h)	72.6° 05:35	8.27	98%	83.0°
2046-09-14 Fri	53	—	unknown	03:35–05:30 (good, 1.92 h)	72.6° 05:35	8.33	100%	71.1°
2046-09-15 Sat	38	—	unknown	00:25–05:30 (marginal, 5.08 h)	72.6° 05:30	8.38	100%	59.3°
2046-09-16 Sun	27	—	unknown	00:35–05:30 (marginal, 4.92 h)	72.6° 05:25	8.43	97%	47.4°
2046-09-17 Mon	18	—	unknown	01:30–05:35 (marginal, 4.08 h)	72.6° 05:20	8.49	94%	35.6°
2046-09-18 Tue	17	—	unknown	00:30–05:35 (marginal, 5.08 h)	72.6° 05:20	8.54	88%	23.7°
2046-09-19 Wed	22	—	unknown	00:10–05:35 (marginal, 5.42 h)	72.6° 05:15	8.59	82%	11.7°
2046-09-20 Thu	31	—	unknown	23:50–05:35 (marginal, 5.75 h)	72.6° 05:10	8.64	73%	0.6°
2046-09-21 Fri	44	—	unknown	23:35–05:35 (marginal, 6.0 h)	72.6° 05:05	8.69	64%	12.7°
2046-09-22 Sat	62	—	unknown	00:40–04:45 (good, 4.08 h)	72.6° 05:00	8.74	54%	25.3°
2046-09-23 Sun	76	—	unknown	23:50–05:40 (good, 5.83 h)	72.6° 05:00	8.79	44%	38.3°
2046-09-24 Mon	88	—	unknown	23:50–05:40 (good, 5.83 h)	72.6° 04:55	8.84	33%	51.7°
2046-09-25 Tue	97	—	unknown	23:45–05:40 (good, 5.92 h)	72.6° 04:50	8.89	23%	65.5°
2046-09-26 Wed	100	—	unknown	23:40–05:45 (good, 6.08 h)	72.6° 04:45	8.94	14%	79.8°
2046-09-27 Thu	100	—	unknown	23:35–05:45 (good, 6.17 h)	72.6° 04:40	8.99	7%	94.5°
2046-09-28 Fri	100	—	unknown	23:30–05:45 (good, 6.25 h)	72.6° 04:40	9.04	2%	109.5°
2046-09-29 Sat	100	—	unknown	23:30–05:45 (good, 6.25 h)	72.6° 04:35	9.09	0%	124.8°
2046-09-30 Sun	100	—	unknown	23:25–05:50 (good, 6.42 h)	72.6° 04:30	9.14	1%	140.1°
2046-10-01 Mon	100	—	unknown	23:20–05:50 (good, 6.5 h)	72.6° 04:25	9.19	5%	155.2°
2046-10-02 Tue	100	—	unknown	23:15–05:50 (good, 6.58 h)	72.6° 04:25	9.24	12%	170.0°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2046-09-03&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.