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 V1057 Cyg: 05-01 (81), 04-29 (80), 04-30 (79), 04-28 (78), 04-27 (77) — by astronomy; check the weather when the night is within four days.

2036-04-02astronomy score per night — click a bar for that night2036-05-01

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2036-04-02 Wed	53	—	unknown	03:20–05:25 (good, 2.08 h)	87.3° 09:35	8.0	38%	104.4°
2036-04-03 Thu	55	—	unknown	03:15–05:25 (good, 2.17 h)	87.3° 09:30	7.94	49%	110.7°
2036-04-04 Fri	54	—	unknown	03:15–05:20 (good, 2.08 h)	87.3° 09:25	7.88	61%	116.0°
2036-04-05 Sat	54	—	unknown	03:15–05:20 (good, 2.08 h)	87.3° 09:20	7.83	72%	119.7°
2036-04-06 Sun	55	—	unknown	03:10–05:20 (good, 2.17 h)	87.3° 09:15	7.77	81%	121.5°
2036-04-07 Mon	48	—	unknown	03:10–05:15 (good, 2.08 h)	87.3° 09:15	7.72	89%	121.2°
2036-04-08 Tue	47	—	unknown	03:10–05:15 (good, 2.08 h)	87.3° 09:10	7.66	95%	118.7°
2036-04-09 Wed	45	—	unknown	03:10–05:15 (good, 2.08 h)	87.3° 09:05	7.6	99%	114.6°
2036-04-10 Thu	41	—	unknown	03:10–05:10 (good, 2.0 h)	87.3° 09:00	7.55	100%	109.1°
2036-04-11 Fri	39	—	unknown	03:10–05:10 (good, 2.0 h)	87.3° 08:55	7.49	98%	102.9°
2036-04-12 Sat	36	—	unknown	03:10–05:05 (good, 1.92 h)	87.3° 08:55	7.43	95%	96.2°
2036-04-13 Sun	35	—	unknown	03:10–05:05 (good, 1.92 h)	87.3° 08:50	7.38	89%	89.5°
2036-04-14 Mon	36	—	unknown	03:05–05:05 (good, 2.0 h)	87.3° 08:45	7.32	82%	83.0°
2036-04-15 Tue	37	—	unknown	02:55–05:00 (good, 2.08 h)	87.3° 08:40	7.26	74%	76.8°
2036-04-16 Wed	40	—	unknown	02:45–05:00 (good, 2.25 h)	87.3° 08:35	7.2	66%	71.2°
2036-04-17 Thu	44	—	unknown	02:35–04:55 (good, 2.33 h)	87.3° 08:35	7.14	56%	66.4°
2036-04-18 Fri	53	—	unknown	02:15–04:55 (good, 2.67 h)	87.3° 08:30	7.09	47%	62.6°
2036-04-19 Sat	60	—	unknown	02:10–04:55 (good, 2.75 h)	87.3° 08:25	7.03	37%	59.9°
2036-04-20 Sun	66	—	unknown	02:05–04:50 (good, 2.75 h)	87.3° 08:20	6.97	28%	58.5°
2036-04-21 Mon	70	—	unknown	02:05–04:50 (good, 2.75 h)	87.3° 08:20	6.91	20%	58.8°
2036-04-22 Tue	71	—	unknown	02:00–04:45 (good, 2.75 h)	87.3° 08:15	6.85	13%	60.5°
2036-04-23 Wed	73	—	unknown	01:55–04:45 (good, 2.83 h)	87.3° 08:10	6.8	7%	63.9°
2036-04-24 Thu	74	—	unknown	01:50–04:45 (good, 2.92 h)	87.3° 08:05	6.74	3%	68.5°
2036-04-25 Fri	75	—	unknown	01:45–04:40 (good, 2.92 h)	87.3° 08:00	6.68	0%	74.3°
2036-04-26 Sat	76	—	unknown	01:45–04:40 (good, 2.92 h)	87.3° 08:00	6.62	0%	81.0°
2036-04-27 Sun	77	—	unknown	01:40–04:40 (good, 3.0 h)	87.3° 07:55	6.56	3%	88.1°
2036-04-28 Mon	78	—	unknown	01:35–04:35 (good, 3.0 h)	87.3° 07:50	6.5	8%	95.4°
2036-04-29 Tue	80	—	unknown	01:30–04:35 (good, 3.08 h)	87.3° 07:45	6.45	15%	102.6°
2036-04-30 Wed	79	—	unknown	01:30–04:30 (good, 3.0 h)	87.3° 07:40	6.39	25%	109.1°
2036-05-01 Thu	81	—	unknown	01:25–04:30 (good, 3.08 h)	87.3° 07:40	6.33	35%	114.7°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2036-04-02&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.