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), 04-05 (49), 04-04 (46) — by astronomy; check the weather when the night is within four days.

2043-03-10astronomy score per night — click a bar for that night2043-04-08

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2043-03-10 Tue	29	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:10	9.23	0%	54.7°
2043-03-11 Wed	30	—	unknown	04:05–05:10 (good, 1.08 h)	71.1° 09:05	9.18	0%	62.3°
2043-03-12 Thu	30	—	unknown	04:00–05:05 (good, 1.08 h)	71.1° 09:00	9.13	3%	71.3°
2043-03-13 Fri	31	—	unknown	03:55–05:05 (good, 1.17 h)	71.1° 08:55	9.08	9%	81.1°
2043-03-14 Sat	32	—	unknown	03:50–05:05 (good, 1.25 h)	71.1° 08:55	9.03	17%	91.1°
2043-03-15 Sun	32	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:50	8.98	27%	101.0°
2043-03-16 Mon	34	—	unknown	03:45–05:00 (good, 1.25 h)	71.1° 08:45	8.93	38%	110.3°
2043-03-17 Tue	35	—	unknown	03:40–05:00 (good, 1.33 h)	71.1° 08:40	8.88	49%	118.7°
2043-03-18 Wed	34	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:35	8.83	60%	125.6°
2043-03-19 Thu	34	—	unknown	03:35–04:55 (good, 1.33 h)	71.1° 08:35	8.78	70%	130.6°
2043-03-20 Fri	34	—	unknown	03:35–04:50 (good, 1.25 h)	71.1° 08:30	8.73	79%	133.1°
2043-03-21 Sat	32	—	unknown	03:30–04:50 (good, 1.33 h)	71.1° 08:25	8.68	87%	132.8°
2043-03-22 Sun	32	—	unknown	03:30–04:50 (good, 1.33 h)	71.1° 08:20	8.62	93%	130.0°
2043-03-23 Mon	31	—	unknown	03:25–04:45 (good, 1.33 h)	71.1° 08:15	8.57	97%	125.2°
2043-03-24 Tue	31	—	unknown	03:25–04:45 (good, 1.33 h)	71.1° 08:15	8.52	100%	118.9°
2043-03-25 Wed	29	—	unknown	03:25–04:45 (good, 1.33 h)	71.1° 08:10	8.47	100%	111.7°
2043-03-26 Thu	27	—	unknown	03:25–04:40 (good, 1.25 h)	71.1° 08:05	8.41	98%	103.9°
2043-03-27 Fri	25	—	unknown	03:25–04:40 (good, 1.25 h)	71.1° 08:00	8.36	95%	95.9°
2043-03-28 Sat	24	—	unknown	04:30–05:35 (good, 1.08 h)	71.1° 08:55	8.31	90%	87.7°
2043-03-29 Sun	24	—	unknown	04:30–05:35 (good, 1.08 h)	71.1° 08:55	8.25	84%	79.7°
2043-03-30 Mon	25	—	unknown	04:20–05:35 (good, 1.25 h)	71.1° 08:50	8.2	76%	71.9°
2043-03-31 Tue	26	—	unknown	04:10–05:30 (good, 1.33 h)	71.1° 08:45	8.14	68%	64.5°
2043-04-01 Wed	28	—	unknown	04:00–05:30 (good, 1.5 h)	71.1° 08:40	8.09	58%	57.8°
2043-04-02 Thu	33	—	unknown	03:35–05:30 (good, 1.92 h)	71.1° 08:40	8.03	49%	52.2°
2043-04-03 Fri	41	—	unknown	03:35–05:25 (good, 1.83 h)	71.1° 08:35	7.98	38%	48.3°
2043-04-04 Sat	46	—	unknown	03:30–05:25 (good, 1.92 h)	71.1° 08:30	7.92	29%	46.7°
2043-04-05 Sun	49	—	unknown	03:25–05:20 (good, 1.92 h)	71.1° 08:25	7.87	19%	47.9°
2043-04-06 Mon	50	—	unknown	03:20–05:20 (good, 2.0 h)	71.1° 08:20	7.81	11%	52.0°
2043-04-07 Tue	52	—	unknown	03:15–05:20 (good, 2.08 h)	71.1° 08:20	7.76	5%	58.6°
2043-04-08 Wed	52	—	unknown	03:15–05:15 (good, 2.0 h)	71.1° 08:15	7.7	1%	67.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2043-03-10&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.