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: 08-16 (65), 08-15 (63), 08-14 (59), 08-13 (57), 08-12 (56) — by astronomy; check the weather when the night is within four days.

2045-07-18astronomy score per night — click a bar for that night2045-08-16

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2045-07-18 Tue	6	—	unknown	04:15–04:50 (marginal, 0.58 h)	72.6° 09:20	5.15	27%	119.5°
2045-07-19 Wed	7	—	unknown	04:10–04:55 (marginal, 0.75 h)	72.6° 09:15	5.2	38%	133.5°
2045-07-20 Thu	10	—	unknown	04:05–04:10 (good, 0.08 h)	72.6° 09:10	5.24	48%	147.2°
2045-07-21 Fri	11	—	unknown	04:05–04:10 (good, 0.08 h)	72.6° 09:10	5.29	59%	160.4°
2045-07-22 Sat	12	—	unknown	04:00–04:10 (good, 0.17 h)	72.6° 09:05	5.34	69%	173.3°
2045-07-23 Sun	14	—	unknown	03:55–04:10 (good, 0.25 h)	72.6° 09:00	5.39	78%	173.9°
2045-07-24 Mon	17	—	unknown	03:50–04:15 (good, 0.42 h)	72.6° 08:55	5.44	86%	161.6°
2045-07-25 Tue	19	—	unknown	03:45–04:15 (good, 0.5 h)	72.6° 08:55	5.49	92%	149.4°
2045-07-26 Wed	18	—	unknown	03:50–04:15 (good, 0.42 h)	72.6° 08:50	5.55	96%	137.3°
2045-07-27 Thu	19	—	unknown	03:50–04:20 (good, 0.5 h)	72.6° 08:45	5.6	99%	125.3°
2045-07-28 Fri	18	—	unknown	03:50–04:20 (good, 0.5 h)	72.6° 08:40	5.65	100%	113.4°
2045-07-29 Sat	16	—	unknown	03:55–04:20 (good, 0.42 h)	72.6° 08:35	5.71	99%	101.6°
2045-07-30 Sun	14	—	unknown	04:20–04:25 (good, 0.08 h)	72.6° 08:35	5.76	96%	89.8°
2045-07-31 Mon	13	—	unknown	03:05–04:25 (marginal, 1.33 h)	72.6° 08:30	5.81	92%	77.9°
2045-08-01 Tue	11	—	unknown	03:05–04:25 (marginal, 1.33 h)	72.6° 08:25	5.87	86%	66.0°
2045-08-02 Wed	10	—	unknown	03:05–04:30 (marginal, 1.42 h)	72.6° 08:20	5.93	79%	53.9°
2045-08-03 Thu	10	—	unknown	03:00–04:30 (marginal, 1.5 h)	72.6° 08:15	5.98	70%	41.7°
2045-08-04 Fri	12	—	unknown	02:55–04:30 (marginal, 1.58 h)	72.6° 08:15	6.04	61%	29.3°
2045-08-05 Sat	17	—	unknown	02:40–04:35 (marginal, 1.92 h)	72.6° 08:10	6.09	51%	16.6°
2045-08-06 Sun	23	—	unknown	03:25–04:35 (good, 1.17 h)	72.6° 08:05	6.15	40%	3.6°
2045-08-07 Mon	29	—	unknown	03:10–04:35 (good, 1.42 h)	72.6° 08:00	6.21	30%	10.2°
2045-08-08 Tue	36	—	unknown	03:00–04:35 (good, 1.58 h)	72.6° 08:00	6.26	20%	24.1°
2045-08-09 Wed	44	—	unknown	02:50–04:40 (good, 1.83 h)	72.6° 07:55	6.32	11%	38.5°
2045-08-10 Thu	50	—	unknown	02:45–04:40 (good, 1.92 h)	72.6° 07:50	6.38	5%	53.3°
2045-08-11 Fri	52	—	unknown	02:40–04:40 (good, 2.0 h)	72.6° 07:45	6.44	1%	68.5°
2045-08-12 Sat	56	—	unknown	02:35–04:45 (good, 2.17 h)	72.6° 07:40	6.49	0%	83.7°
2045-08-13 Sun	57	—	unknown	02:30–04:45 (good, 2.25 h)	72.6° 07:40	6.55	2%	98.9°
2045-08-14 Mon	59	—	unknown	02:30–04:45 (good, 2.25 h)	72.6° 07:35	6.61	7%	113.9°
2045-08-15 Tue	63	—	unknown	02:25–04:50 (good, 2.42 h)	72.6° 07:30	6.67	14%	128.6°
2045-08-16 Wed	65	—	unknown	02:20–04:50 (good, 2.5 h)	72.6° 07:25	6.72	24%	142.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-07-18&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.