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: 04-19 (100), 04-20 (100), 04-21 (100), 04-22 (100), 04-23 (100) — by astronomy; check the weather when the night is within four days.

2036-04-15astronomy score per night — click a bar for that night2036-05-14

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-04-15 Tue	66	—	unknown	00:25–05:00 (good, 4.58 h)	87.1° 06:20	7.26	74%	59.0°
2036-04-16 Wed	84	—	unknown	00:20–05:00 (good, 4.67 h)	87.1° 06:15	7.2	66%	58.3°
2036-04-17 Thu	91	—	unknown	00:20–04:55 (good, 4.58 h)	87.1° 06:10	7.14	56%	59.2°
2036-04-18 Fri	97	—	unknown	00:15–04:55 (good, 4.67 h)	87.1° 06:10	7.09	47%	61.4°
2036-04-19 Sat	100	—	unknown	00:10–04:55 (good, 4.75 h)	87.1° 06:05	7.03	37%	64.9°
2036-04-20 Sun	100	—	unknown	00:05–04:50 (good, 4.75 h)	87.1° 06:00	6.97	28%	69.5°
2036-04-21 Mon	100	—	unknown	00:00–04:50 (good, 4.83 h)	87.1° 05:55	6.91	20%	74.9°
2036-04-22 Tue	100	—	unknown	00:00–04:45 (good, 4.75 h)	87.1° 05:50	6.85	13%	81.0°
2036-04-23 Wed	100	—	unknown	23:55–04:45 (good, 4.83 h)	87.1° 05:50	6.8	7%	87.6°
2036-04-24 Thu	100	—	unknown	23:50–04:45 (good, 4.92 h)	87.1° 05:45	6.74	3%	94.4°
2036-04-25 Fri	100	—	unknown	23:45–04:40 (good, 4.92 h)	87.1° 05:40	6.68	0%	101.2°
2036-04-26 Sat	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.62	0%	107.6°
2036-04-27 Sun	100	—	unknown	23:40–04:40 (good, 5.0 h)	87.1° 05:35	6.56	3%	113.3°
2036-04-28 Mon	100	—	unknown	23:35–04:35 (good, 5.0 h)	87.1° 05:30	6.5	8%	117.9°
2036-04-29 Tue	100	—	unknown	23:30–04:35 (good, 5.08 h)	87.1° 05:25	6.45	15%	120.7°
2036-04-30 Wed	100	—	unknown	23:30–04:30 (good, 5.0 h)	87.1° 05:20	6.39	25%	121.5°
2036-05-01 Thu	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.33	35%	120.2°
2036-05-02 Fri	100	—	unknown	23:25–04:30 (good, 5.08 h)	87.1° 05:15	6.27	46%	116.9°
2036-05-03 Sat	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:10	6.21	58%	112.0°
2036-05-04 Sun	100	—	unknown	23:25–04:25 (good, 5.0 h)	87.1° 05:05	6.16	69%	105.9°
2036-05-05 Mon	100	—	unknown	23:30–04:25 (good, 4.92 h)	87.1° 05:00	6.1	78%	99.2°
2036-05-06 Tue	83	—	unknown	23:50–04:20 (good, 4.5 h)	87.1° 04:55	6.04	87%	92.1°
2036-05-07 Wed	77	—	unknown	00:40–04:20 (good, 3.67 h)	87.1° 04:55	5.99	93%	85.0°
2036-05-08 Thu	67	—	unknown	01:25–04:20 (good, 2.92 h)	87.1° 04:50	5.93	98%	78.2°
2036-05-09 Fri	59	—	unknown	02:00–04:15 (good, 2.25 h)	87.1° 04:45	5.87	100%	72.0°
2036-05-10 Sat	54	—	unknown	03:15–04:15 (good, 1.0 h)	87.1° 04:40	5.82	99%	66.7°
2036-05-11 Sun	53	—	unknown	22:25–04:55 (marginal, 6.5 h)	87.1° 04:40	5.76	97%	62.6°
2036-05-12 Mon	56	—	unknown	01:30–02:50 (good, 1.33 h)	87.1° 04:35	5.71	93%	59.8°
2036-05-13 Tue	83	—	unknown	22:35–04:10 (good, 5.58 h)	87.1° 04:30	5.65	87%	58.6°
2036-05-14 Wed	89	—	unknown	22:30–04:10 (good, 5.67 h)	87.1° 04:25	5.6	80%	58.9°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-04-15&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.