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 Vega: 04-01 (100), 04-02 (100), 04-03 (100), 04-04 (100), 04-05 (100) — by astronomy; check the weather when the night is within four days.

2027-03-14astronomy score per night — click a bar for that night2027-04-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2027-03-14 Sun	91	—	unknown	01:35–05:05 (good, 3.5 h)	87.1° 07:30	9.04	42%	109.4°
2027-03-15 Mon	90	—	unknown	01:35–05:00 (good, 3.42 h)	87.1° 07:25	8.99	53%	112.9°
2027-03-16 Tue	90	—	unknown	01:35–05:00 (good, 3.42 h)	87.1° 07:20	8.94	64%	115.1°
2027-03-17 Wed	89	—	unknown	01:35–05:00 (good, 3.42 h)	87.1° 07:15	8.89	75%	115.6°
2027-03-18 Thu	86	—	unknown	01:30–04:55 (good, 3.42 h)	87.1° 07:15	8.84	84%	114.4°
2027-03-19 Fri	75	—	unknown	01:35–04:55 (good, 3.33 h)	87.1° 07:10	8.79	92%	111.6°
2027-03-20 Sat	70	—	unknown	01:35–04:55 (good, 3.33 h)	87.1° 07:05	8.73	97%	107.5°
2027-03-21 Sun	64	—	unknown	01:35–04:50 (good, 3.25 h)	87.1° 07:00	8.68	100%	102.4°
2027-03-22 Mon	59	—	unknown	01:45–04:50 (good, 3.08 h)	87.1° 06:55	8.63	100%	96.7°
2027-03-23 Tue	56	—	unknown	01:55–04:45 (good, 2.83 h)	87.1° 06:55	8.58	97%	90.8°
2027-03-24 Wed	54	—	unknown	01:55–04:45 (good, 2.83 h)	87.1° 06:50	8.53	92%	85.0°
2027-03-25 Thu	55	—	unknown	01:30–04:45 (good, 3.25 h)	87.1° 06:45	8.47	86%	79.6°
2027-03-26 Fri	57	—	unknown	01:15–04:40 (good, 3.42 h)	87.1° 06:40	8.42	78%	74.8°
2027-03-27 Sat	63	—	unknown	01:05–05:40 (good, 3.58 h)	87.1° 07:35	8.37	70%	70.7°
2027-03-28 Sun	74	—	unknown	01:40–05:40 (good, 4.0 h)	87.1° 07:35	8.31	60%	67.5°
2027-03-29 Mon	84	—	unknown	01:35–05:35 (good, 4.0 h)	87.1° 07:30	8.26	51%	65.4°
2027-03-30 Tue	94	—	unknown	01:30–05:35 (good, 4.08 h)	87.1° 07:25	8.2	42%	64.4°
2027-03-31 Wed	98	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.15	32%	64.5°
2027-04-01 Thu	100	—	unknown	01:25–05:30 (good, 4.08 h)	87.1° 07:20	8.1	24%	65.8°
2027-04-02 Fri	100	—	unknown	01:20–05:30 (good, 4.17 h)	87.1° 07:15	8.04	16%	68.2°
2027-04-03 Sat	100	—	unknown	01:15–05:25 (good, 4.17 h)	87.1° 07:10	7.99	10%	71.7°
2027-04-04 Sun	100	—	unknown	01:10–05:25 (good, 4.25 h)	87.1° 07:05	7.93	5%	76.0°
2027-04-05 Mon	100	—	unknown	01:10–05:20 (good, 4.17 h)	87.1° 07:00	7.87	1%	81.1°
2027-04-06 Tue	100	—	unknown	01:05–05:20 (good, 4.25 h)	87.1° 07:00	7.82	0%	86.6°
2027-04-07 Wed	100	—	unknown	01:00–05:20 (good, 4.33 h)	87.1° 06:55	7.76	1%	92.4°
2027-04-08 Thu	100	—	unknown	00:55–05:15 (good, 4.33 h)	87.1° 06:50	7.71	5%	98.2°
2027-04-09 Fri	100	—	unknown	00:50–05:15 (good, 4.42 h)	87.1° 06:45	7.65	10%	103.7°
2027-04-10 Sat	100	—	unknown	00:50–05:10 (good, 4.33 h)	87.1° 06:40	7.59	18%	108.6°
2027-04-11 Sun	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:40	7.54	28%	112.4°
2027-04-12 Mon	100	—	unknown	00:45–05:10 (good, 4.42 h)	87.1° 06:35	7.48	38%	114.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2027-03-14&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.