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Lunar time unit classes

Source: R/cal0_time_lunar.R
calendar_time_lunar.Rd

Time unit constructors for the lunar time system where the boundary of each day is at sunrise, sunset, or noon. This calendar is intended to be built on by other calendars to add common time components.

Usage

cal_time_lunar

Format

A location-based calendar containing lunar time units.

Value

An S3 list of class c("cal_time_lunar", "mt_calendar") containing the named time unit classes of the lunar calendar. Each unit is accessible via $ notation and calling it with a step size and location produces a time granule (e.g., 1 synodic month granule as cal_time_lunar$month(1L, lat = 0, lon = 0)). Because lunar phases depend on the observer's position, each unit constructor requires lat and lon arguments.

Details

The following time units are available in the lunar calendar systems.

  • month(): Synodic month unit

  • phase(): Synodic phase unit

See also

cal_time_civil

Examples

# Find the time of a new moon in the Gregorian calendar
t <- linear_time(Sys.Date(), cal_time_lunar$month(1L, lat = -37.8136, lon = 144.9631))
datetime(t, tz = "Australia/Melbourne")
#> <mixtime[1]>
#> [1] 2026-05-17 06:03:23 AEST