Tai.Time.monotonic_to_date_time-exclamation-mark

You're seeing just the function monotonic_to_date_time-exclamation-mark, go back to Tai.Time module for more information.
Link to this function

monotonic_to_date_time!(mono, unit \\ :microsecond, calendar \\ Calendar.ISO)

Specs

monotonic_to_date_time!(
  integer(),
  :native | System.time_unit(),
  Calendar.calendar()
) :: DateTime.t()