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: 02-19 (20), 02-18 (19), 02-17 (18), 02-16 (17), 02-15 (16) — by astronomy; check the weather when the night is within four days.

2029-01-21astronomy score per night — click a bar for that night2029-02-19

night of	astronomy	weather	overall	best window	highest	dark h	Moon	Moon sep.
2029-01-21 Sun	13	—	unknown	19:05–19:10 (good, 0.08 h)	87.2° 13:15	11.08	42%	62.2°
2029-01-22 Mon	12	—	unknown	19:05–20:10 (marginal, 1.08 h)	87.2° 13:15	11.05	51%	67.8°
2029-01-23 Tue	10	—	unknown	19:05–20:00 (marginal, 0.92 h)	87.2° 13:10	11.02	61%	74.2°
2029-01-24 Wed	9	—	unknown	19:05–19:55 (marginal, 0.83 h)	87.2° 13:05	10.99	70%	81.3°
2029-01-25 Thu	9	—	unknown	19:05–19:50 (marginal, 0.75 h)	87.2° 13:00	10.96	79%	88.8°
2029-01-26 Fri	8	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.2° 12:55	10.94	87%	96.7°
2029-01-27 Sat	8	—	unknown	19:10–19:50 (marginal, 0.67 h)	87.2° 12:55	10.91	93%	104.5°
2029-01-28 Sun	8	—	unknown	19:10–19:45 (marginal, 0.58 h)	87.2° 12:50	10.88	98%	112.0°
2029-01-29 Mon	8	—	unknown	19:10–19:40 (marginal, 0.5 h)	87.2° 12:45	10.84	100%	118.6°
2029-01-30 Tue	8	—	unknown	19:10–19:35 (marginal, 0.42 h)	87.2° 12:40	10.81	99%	123.6°
2029-01-31 Wed	8	—	unknown	19:15–19:30 (marginal, 0.25 h)	87.2° 12:35	10.78	96%	126.5°
2029-02-01 Thu	8	—	unknown	05:40–06:00 (marginal, 0.33 h)	87.2° 12:35	10.75	90%	126.6°
2029-02-02 Fri	8	—	unknown	05:35–06:00 (marginal, 0.42 h)	87.2° 12:30	10.71	82%	124.0°
2029-02-03 Sat	8	—	unknown	05:30–06:00 (marginal, 0.5 h)	87.2° 12:25	10.68	72%	119.1°
2029-02-04 Sun	8	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:20	10.65	61%	112.6°
2029-02-05 Mon	8	—	unknown	05:25–05:55 (marginal, 0.5 h)	87.2° 12:15	10.61	50%	105.1°
2029-02-06 Tue	8	—	unknown	05:20–05:55 (marginal, 0.58 h)	87.2° 12:15	10.58	39%	97.2°
2029-02-07 Wed	9	—	unknown	05:15–05:55 (marginal, 0.67 h)	87.2° 12:10	10.54	28%	89.1°
2029-02-08 Thu	11	—	unknown	05:50–05:55 (good, 0.08 h)	87.2° 12:05	10.5	19%	81.3°
2029-02-09 Fri	10	—	unknown	05:45–05:50 (good, 0.08 h)	87.2° 12:00	10.47	12%	73.8°
2029-02-10 Sat	12	—	unknown	05:40–05:50 (good, 0.17 h)	87.2° 11:55	10.43	6%	67.1°
2029-02-11 Sun	13	—	unknown	05:35–05:50 (good, 0.25 h)	87.2° 11:50	10.39	2%	61.3°
2029-02-12 Mon	14	—	unknown	05:30–05:50 (good, 0.33 h)	87.2° 11:45	10.35	0%	56.9°
2029-02-13 Tue	14	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:40	10.31	0%	54.1°
2029-02-14 Wed	15	—	unknown	05:25–05:45 (good, 0.33 h)	87.2° 11:40	10.27	2%	53.1°
2029-02-15 Thu	16	—	unknown	05:20–05:45 (good, 0.42 h)	87.2° 11:35	10.23	6%	54.0°
2029-02-16 Fri	17	—	unknown	05:15–05:45 (good, 0.5 h)	87.2° 11:30	10.19	11%	56.7°
2029-02-17 Sat	18	—	unknown	05:10–05:40 (good, 0.5 h)	87.2° 11:25	10.15	18%	60.8°
2029-02-18 Sun	19	—	unknown	05:05–05:40 (good, 0.58 h)	87.2° 11:20	10.11	25%	66.1°
2029-02-19 Mon	20	—	unknown	05:05–05:40 (good, 0.58 h)	87.2° 11:20	10.07	34%	72.2°

Download: CSV · JSON

💡 API

curl -sS "https://devops.majbase.com/rozhen-planner/calendar-api?target=M31&date=2029-01-21&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.