Linear time points

linear_time() creates a vector of linear time points with a specified chronon (smallest time unit). This function is useful for creating custom time representations that aren't covered by the convenience functions like yearmonth() or yearweek().

Usage

linear_time(
  data,
  chronon = time_chronon(data),
  discrete = TRUE,
  calendar = time_calendar(data),
  granules = chronon_granules(chronon),
  tz = tz_name(data)
)

Arguments

data

Input data to convert to linear time. Can be:

• Numeric values (interpreted as chronons since Unix epoch)

• Character strings (parsed as dates/times)

• Date or POSIXct objects

• Other time objects

chronon

A time unit expression representing the chronon (smallest indivisible time unit), evaluated in the context of calendar. Use unquoted expressions like month(1L) or hour(1L). Chronons from a specific calendar can also be used (e.g. cal_isoweek$week(1L)). Defaults to the time chronon of the input data (time_chronon(data)).

discrete

Logical. If TRUE (default), returns integer chronons since Unix epoch (discrete time model). If FALSE, returns fractional chronons allowing representation of partial time units (continuous time model).

calendar

Calendar system used to evaluate chronon and granules. Defaults to time_calendar(data) for existing time objects. Common options include cal_gregorian and cal_isoweek.

granules

A list of time unit expressions representing structural units larger than the chronon (e.g., years, quarters, months). These define how time is displayed and grouped. Use unquoted expressions like list(year(1L), quarter(1L)). Defaults to an empty list.

tz

Time zone for the time representation. Defaults to the time zone of the input data (tz_name(data)). Time zones need to be valid identifiers for the IANA time zone database (tzdb::tzdb_names())

Value

A mt_linear time vector, which is a subclass of mt_time.

See also

• new_linear_time_fn() for creating reusable linear time functions

• yearmonth(), yearquarter(), year() for Gregorian time representations

• yearweek() for ISO 8601 week-based time

• cal_gregorian, cal_isoweek for calendar systems

Examples

# Hourly time with year-month-day granules
linear_time(
  Sys.time(),
  chronon = hour(1L),
  granules = list(year(1L), month(1L), day(1L))
)
#> <mixtime[1]>
#> [1] 2026-Feb-24-h2

# Monthly chronons with year-quarter granules
linear_time(
  Sys.Date(),
  chronon = month(1L),
  granules = list(year(1L), quarter(1L))
)
#> <mixtime[1]>
#> [1] 2026-Q1-M1

# Discrete vs continuous time
linear_time(Sys.time(), chronon = day(1L), discrete = TRUE)
#> <mixtime[1]>
#> [1] 2026-Feb-24
linear_time(Sys.time(), chronon = day(1L), discrete = FALSE)
#> <mixtime[1]>
#> [1] 2026-Feb-24-9.3%

# ISO week calendar with week-day structure
linear_time(
  Sys.Date(),
  chronon = day(1L),
  granules = list(year(1L), week(1L)),
  calendar = cal_isoweek
)
#> <mixtime[1]>
#> [1] 2026-W9-Tue