stepmetrics (version 1.0.3)

define_day_indices: Generate sequential day indices from ISO 8601 timestamps

Description

Converts a vector of ISO 8601 timestamps into sequential day indices (1, 2, 3, ...), where each unique calendar date corresponds to a unique integer. This is useful for looping over or summarizing data by day when working with minute-level time series from wearables.

Usage

define_day_indices(ts)

Value

An integer vector of the same length as `ts`, where each element gives the index of the day the timestamp belongs to. The first unique date encountered is assigned index `1`, the second `2`, and so on.

Arguments

ts

Character vector of ISO 8601 timestamps (e.g., `"2024-06-26T23:45:00+0100"`). Time zone offsets are handled correctly when converting to `Date`.

See Also

[as.POSIXct()], [as.Date()]

Examples

ts <- c("2024-06-26T23:45:00+0100",
        "2024-06-27T00:15:00+0100",
        "2024-06-27T14:30:00+0100")
define_day_indices(ts)
# Returns: c(1, 2, 2)