Lunar phase at date, as an angle in degrees. An angle of 0 means a new moon, 90 degrees means the first quarter, 180 means a full moon, and 270 degrees means the last quarter.
Examples
april2025 <- seq(as.Date("2025-04-01"), as.Date("2025-04-30"), by = "1 day")
lunar_phase(april2025)
#> [1] 35.87571 49.68103 63.14151 76.19938 88.83943 101.08071 112.96536
#> [8] 124.54784 135.88624 147.03637 158.04870 168.96764 179.83223 190.67757
#> [15] 201.53670 212.44314 223.43391 234.55221 245.84850 257.37951 269.20513
#> [22] 281.38360 293.96466 306.97947 320.42760 334.26406 348.39227 2.66872
#> [29] 16.92140 30.97752