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: 08-22 (80), 08-23 (80), 08-24 (80), 08-21 (77), 08-20 (75) — by astronomy; check the weather when the night is within four days.

2045-08-04astronomy score per night — click a bar for that night2045-09-02

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
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°
2045-08-17 Thu	67	—	unknown	02:15–04:50 (good, 2.58 h)	72.6° 07:20	6.78	34%	156.5°
2045-08-18 Fri	70	—	unknown	02:15–04:55 (good, 2.67 h)	72.6° 07:20	6.84	44%	169.8°
2045-08-19 Sat	73	—	unknown	02:10–04:55 (good, 2.75 h)	72.6° 07:15	6.9	55%	177.0°
2045-08-20 Sun	75	—	unknown	02:05–04:55 (good, 2.83 h)	72.6° 07:10	6.95	64%	164.6°
2045-08-21 Mon	77	—	unknown	02:00–04:55 (good, 2.92 h)	72.6° 07:05	7.01	74%	152.4°
2045-08-22 Tue	80	—	unknown	02:05–05:00 (good, 2.92 h)	72.6° 07:05	7.07	82%	140.3°
2045-08-23 Wed	80	—	unknown	02:00–05:00 (good, 3.0 h)	72.6° 07:00	7.13	88%	128.3°
2045-08-24 Thu	80	—	unknown	02:00–05:00 (good, 3.0 h)	72.6° 06:55	7.18	94%	116.5°
2045-08-25 Fri	64	—	unknown	02:05–05:05 (good, 3.0 h)	72.6° 06:50	7.24	98%	104.6°
2045-08-26 Sat	53	—	unknown	02:25–05:05 (good, 2.67 h)	72.6° 06:45	7.3	100%	92.8°
2045-08-27 Sun	42	—	unknown	03:35–05:05 (good, 1.5 h)	72.6° 06:45	7.35	100%	80.9°
2045-08-28 Mon	33	—	unknown	05:00–05:05 (good, 0.08 h)	72.6° 06:40	7.41	98%	69.0°
2045-08-29 Tue	25	—	unknown	01:30–05:10 (marginal, 3.67 h)	72.6° 06:35	7.47	95%	56.9°
2045-08-30 Wed	19	—	unknown	01:35–05:10 (marginal, 3.58 h)	72.6° 06:30	7.52	90%	44.8°
2045-08-31 Thu	16	—	unknown	01:30–05:10 (marginal, 3.67 h)	72.6° 06:25	7.58	83%	32.4°
2045-09-01 Fri	20	—	unknown	01:15–05:15 (marginal, 4.0 h)	72.6° 06:25	7.63	75%	19.9°
2045-09-02 Sat	28	—	unknown	01:00–05:15 (marginal, 4.25 h)	72.6° 06:20	7.69	66%	7.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2045-08-04&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.