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 HD 189733: 04-07 (52), 04-08 (52), 04-06 (50), 04-04 (49), 04-05 (49) — by astronomy; check the weather when the night is within four days.

2035-03-10astronomy score per night — click a bar for that night2035-04-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-03-10 Sat	29	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:10	9.23	1%	65.2°
2035-03-11 Sun	30	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.18	5%	75.6°
2035-03-12 Mon	30	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 09:00	9.13	11%	86.4°
2035-03-13 Tue	31	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.09	19%	97.4°
2035-03-14 Wed	32	—	unknown	03:50–05:05 (good, 1.25 h)	71.1° 08:50	9.04	29%	108.3°
2035-03-15 Thu	32	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:50	8.99	40%	118.6°
2035-03-16 Fri	34	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:45	8.94	51%	127.9°
2035-03-17 Sat	35	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:40	8.88	62%	135.4°
2035-03-18 Sun	34	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:35	8.83	73%	140.0°
2035-03-19 Mon	34	—	unknown	03:40–04:55 (good, 1.25 h)	71.1° 08:35	8.78	82%	140.9°
2035-03-20 Tue	32	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:30	8.73	90%	137.7°
2035-03-21 Wed	31	—	unknown	03:35–04:50 (good, 1.25 h)	71.1° 08:25	8.68	96%	131.6°
2035-03-22 Thu	31	—	unknown	03:30–04:50 (good, 1.33 h)	71.1° 08:20	8.63	99%	123.5°
2035-03-23 Fri	28	—	unknown	03:30–04:45 (good, 1.25 h)	71.1° 08:15	8.58	100%	114.4°
2035-03-24 Sat	26	—	unknown	04:35–05:45 (good, 1.17 h)	71.1° 09:15	8.52	99%	104.8°
2035-03-25 Sun	23	—	unknown	04:40–05:45 (good, 1.08 h)	71.1° 09:10	8.47	96%	95.1°
2035-03-26 Mon	21	—	unknown	05:05–05:40 (good, 0.58 h)	71.1° 09:05	8.42	91%	85.5°
2035-03-27 Tue	20	—	unknown	05:20–05:40 (good, 0.33 h)	71.1° 09:00	8.36	85%	76.2°
2035-03-28 Wed	20	—	unknown	05:20–05:40 (good, 0.33 h)	71.1° 08:55	8.31	77%	67.2°
2035-03-29 Thu	21	—	unknown	05:05–05:35 (good, 0.5 h)	71.1° 08:55	8.26	69%	58.8°
2035-03-30 Fri	24	—	unknown	04:25–05:35 (good, 1.17 h)	71.1° 08:50	8.2	60%	51.3°
2035-03-31 Sat	27	—	unknown	04:05–05:30 (good, 1.42 h)	71.1° 08:45	8.15	50%	45.0°
2035-04-01 Sun	31	—	unknown	03:55–05:30 (good, 1.58 h)	71.1° 08:40	8.09	41%	40.7°
2035-04-02 Mon	39	—	unknown	03:35–05:30 (good, 1.92 h)	71.1° 08:40	8.04	31%	39.0°
2035-04-03 Tue	44	—	unknown	03:35–05:25 (good, 1.83 h)	71.1° 08:35	7.98	22%	40.6°
2035-04-04 Wed	49	—	unknown	03:30–05:25 (good, 1.92 h)	71.1° 08:30	7.93	14%	45.2°
2035-04-05 Thu	49	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:25	7.87	8%	52.4°
2035-04-06 Fri	50	—	unknown	03:20–05:20 (good, 2.0 h)	71.1° 08:20	7.82	3%	61.3°
2035-04-07 Sat	52	—	unknown	03:15–05:20 (good, 2.08 h)	71.1° 08:20	7.76	0%	71.5°
2035-04-08 Sun	52	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:15	7.7	0%	82.4°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-03-10&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.