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 North America Nebula: 01-14 (25), 01-15 (21), 01-16 (18), 01-17 (16), 01-25 (16) — by astronomy; check the weather when the night is within four days.

2035-01-14astronomy score per night — click a bar for that night2035-02-12

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2035-01-14 Sun	25	—	unknown	18:55–19:55 (good, 1.0 h)	87.2° 13:45	11.25	26%	60.0°
2035-01-15 Mon	21	—	unknown	18:55–19:45 (good, 0.83 h)	87.2° 13:40	11.23	36%	64.3°
2035-01-16 Tue	18	—	unknown	18:55–19:30 (good, 0.58 h)	87.2° 13:40	11.21	47%	70.1°
2035-01-17 Wed	16	—	unknown	19:00–19:20 (good, 0.33 h)	87.2° 13:35	11.18	58%	76.9°
2035-01-18 Thu	14	—	unknown	18:25–20:25 (marginal, 2.0 h)	87.2° 13:30	11.16	69%	84.5°
2035-01-19 Fri	14	—	unknown	18:25–20:20 (marginal, 1.92 h)	87.2° 13:25	11.14	80%	92.4°
2035-01-20 Sat	14	—	unknown	19:00–19:10 (good, 0.17 h)	87.2° 13:20	11.11	88%	100.3°
2035-01-21 Sun	15	—	unknown	19:00–19:15 (good, 0.25 h)	87.2° 13:20	11.09	95%	107.8°
2035-01-22 Mon	15	—	unknown	19:05–19:15 (good, 0.17 h)	87.2° 13:15	11.06	99%	114.4°
2035-01-23 Tue	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:10	11.03	100%	119.4°
2035-01-24 Wed	14	—	unknown	19:05–19:15 (good, 0.17 h)	87.2° 13:05	11.01	98%	122.5°
2035-01-25 Thu	16	—	unknown	19:05–19:25 (good, 0.33 h)	87.2° 13:05	10.98	94%	123.4°
2035-01-26 Fri	15	—	unknown	19:05–19:20 (good, 0.25 h)	87.2° 13:00	10.95	88%	122.0°
2035-01-27 Sat	13	—	unknown	19:10–19:15 (good, 0.08 h)	87.2° 12:55	10.92	81%	118.9°
2035-01-28 Sun	12	—	unknown	18:35–19:45 (marginal, 1.17 h)	87.2° 12:50	10.89	72%	114.4°
2035-01-29 Mon	10	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.86	63%	108.9°
2035-01-30 Tue	10	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.83	53%	102.9°
2035-01-31 Wed	9	—	unknown	19:15–19:35 (marginal, 0.33 h)	87.2° 12:40	10.8	44%	96.6°
2035-02-01 Thu	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.76	34%	90.1°
2035-02-02 Fri	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.73	26%	83.6°
2035-02-03 Sat	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:25	10.7	18%	77.3°
2035-02-04 Sun	9	—	unknown	05:30–05:55 (marginal, 0.42 h)	87.2° 12:25	10.66	11%	71.4°
2035-02-05 Mon	9	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.63	6%	66.0°
2035-02-06 Tue	10	—	unknown	05:20–06:30 (marginal, 1.17 h)	87.2° 12:15	10.59	2%	61.6°
2035-02-07 Wed	10	—	unknown	05:20–06:25 (marginal, 1.08 h)	87.2° 12:10	10.56	0%	58.4°
2035-02-08 Thu	11	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:10	10.52	0%	56.8°
2035-02-09 Fri	11	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 12:00	10.48	3%	57.1°
2035-02-10 Sat	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 12:00	10.45	7%	59.3°
2035-02-11 Sun	12	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.41	14%	63.3°
2035-02-12 Mon	13	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.37	22%	68.8°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2035-01-14&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.