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: 01-21 (31), 01-20 (30), 01-19 (29), 01-18 (27), 01-17 (25) — by astronomy; check the weather when the night is within four days.

2033-12-23astronomy score per night — click a bar for that night2034-01-21

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2033-12-23 Fri	12	—	unknown	18:40–18:50 (good, 0.17 h)	87.1° 12:50	11.5	5%	57.8°
2033-12-24 Sat	11	—	unknown	18:05–19:15 (marginal, 1.17 h)	87.1° 12:45	11.5	11%	60.8°
2033-12-25 Sun	10	—	unknown	18:40–19:15 (marginal, 0.58 h)	87.1° 12:40	11.5	18%	65.4°
2033-12-26 Mon	9	—	unknown	18:40–19:10 (marginal, 0.5 h)	87.1° 12:40	11.49	28%	71.4°
2033-12-27 Tue	8	—	unknown	18:40–19:05 (marginal, 0.42 h)	87.1° 12:35	11.49	38%	78.2°
2033-12-28 Wed	7	—	unknown	18:40–19:00 (marginal, 0.33 h)	87.1° 12:30	11.48	49%	85.7°
2033-12-29 Thu	7	—	unknown	05:55–06:10 (marginal, 0.25 h)	87.1° 12:25	11.48	60%	93.5°
2033-12-30 Fri	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.47	71%	101.1°
2033-12-31 Sat	8	—	unknown	05:50–06:10 (marginal, 0.33 h)	87.1° 12:20	11.46	81%	108.3°
2034-01-01 Sun	9	—	unknown	05:45–06:10 (marginal, 0.42 h)	87.1° 12:15	11.45	89%	114.6°
2034-01-02 Mon	10	—	unknown	05:40–06:45 (marginal, 1.08 h)	87.1° 12:10	11.44	95%	119.4°
2034-01-03 Tue	9	—	unknown	05:35–06:10 (marginal, 0.58 h)	87.1° 12:05	11.43	99%	122.4°
2034-01-04 Wed	9	—	unknown	05:35–06:10 (marginal, 0.58 h)	87.1° 12:00	11.41	100%	123.2°
2034-01-05 Thu	10	—	unknown	05:30–06:45 (marginal, 1.25 h)	87.1° 11:55	11.4	98%	121.9°
2034-01-06 Fri	10	—	unknown	05:25–06:45 (marginal, 1.33 h)	87.1° 11:50	11.39	95%	118.7°
2034-01-07 Sat	11	—	unknown	05:20–06:45 (marginal, 1.42 h)	87.1° 11:45	11.37	89%	114.1°
2034-01-08 Sun	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 11:45	11.36	82%	108.5°
2034-01-09 Mon	11	—	unknown	06:05–06:10 (good, 0.08 h)	87.1° 11:40	11.34	74%	102.4°
2034-01-10 Tue	12	—	unknown	06:00–06:10 (good, 0.17 h)	87.1° 11:35	11.32	65%	95.9°
2034-01-11 Wed	14	—	unknown	05:55–06:10 (good, 0.25 h)	87.1° 11:30	11.3	56%	89.4°
2034-01-12 Thu	15	—	unknown	05:50–06:10 (good, 0.33 h)	87.1° 11:25	11.29	46%	82.9°
2034-01-13 Fri	17	—	unknown	05:45–06:10 (good, 0.42 h)	87.1° 11:25	11.27	37%	76.7°
2034-01-14 Sat	18	—	unknown	05:35–06:10 (good, 0.58 h)	87.1° 11:20	11.24	28%	70.9°
2034-01-15 Sun	21	—	unknown	05:30–06:10 (good, 0.67 h)	87.1° 11:15	11.22	20%	65.6°
2034-01-16 Mon	23	—	unknown	05:20–06:10 (good, 0.83 h)	87.1° 11:10	11.2	13%	61.3°
2034-01-17 Tue	25	—	unknown	05:15–06:10 (good, 0.92 h)	87.1° 11:10	11.18	7%	58.2°
2034-01-18 Wed	27	—	unknown	05:10–06:10 (good, 1.0 h)	87.1° 11:05	11.16	3%	56.8°
2034-01-19 Thu	29	—	unknown	05:05–06:10 (good, 1.08 h)	87.1° 11:00	11.13	0%	57.3°
2034-01-20 Fri	30	—	unknown	05:00–06:10 (good, 1.17 h)	87.1° 10:55	11.11	0%	59.8°
2034-01-21 Sat	31	—	unknown	05:00–06:05 (good, 1.08 h)	87.1° 10:50	11.08	3%	64.1°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2033-12-23&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.