SpaDES modules commonly use approximate durations that divide with no remainder among themselves. For example, models that simulate based on a "week" timestep, will likely want to fall in lock step with a second module that is a "year" timestep. Since, weeks, months, years don't really have this behaviour because of: leap years, leap seconds, not quite 52 weeks in a year, months that are of different duration, etc. We have generated a set of units that work well together that are based on the astronomical or "Julian" year. In an astronomical year, leap years are added within each year with an extra 1/4 day, (i.e., 1 year == 365.25 days); months are defined as year/12, and weeks as year/52.

dyears(x)

# S4 method for numeric
dyears(x)

dmonths(x)

# S4 method for numeric
dmonths(x)

dweeks(x)

# S4 method for numeric
dweeks(x)

dweek(x)

dmonth(x)

dyear(x)

dsecond(x)

dday(x)

dhour(x)

dNA(x)

# S4 method for ANY
dNA(x)

## Arguments

x numeric. Number of the desired units

## Value

Number of seconds within each unit

## Details

When these units are not correct, a module developer can create their own time unit using, and create a function to calculate the number of seconds in that unit using the "d" prefix (for duration), following the lubridate package standard: dfortnight <- function(x) lubridate::duration(dday(14)). Then the module developer can use "fortnight" as the module's time unit.