Fixed cardinality between time granules

A restricted variant of chronon_cardinality() for time granule pairs whose relationship is a constant, context-independent number (e.g., 60 seconds in a minute, 24 hours in a day). Unlike chronon_cardinality(), methods for this generic do not receive (and must not need) an at time point, and should return the number of unit (n = 1L) x granules that fit within one unit y granule.

Usage

chronon_cardinality_fixed(x, y, ...)

Arguments

x

The finer time granule (e.g. cal_gregorian$month(1L))

y

The coarser time granule (e.g. cal_gregorian$year(1L))

...

Additional arguments for methods.

Value

A single number describing how many unit x time granules fit into a unit y time granule.

Details

Defining a method for chronon_cardinality_fixed() automatically provides a chronon_cardinality() method for the pair (scaled by the requested granule sizes via the list(mt_unit, mt_unit) fallback method), and marks the relationship as safe to use for chronon_divmod()'s graph traversal, where variable (context-dependent) cardinalities cannot be used since no at is available mid-traversal.