Date.add
You're seeing just the function
add, go back to Date module for more information.
Specs
add(Calendar.date(), integer()) :: t()
Adds the number of days to the given date.
The days are counted as Gregorian days. The date is returned in the same calendar as it was given in.
Examples
iex> Date.add(~D[2000-01-03], -2)
~D[2000-01-01]
iex> Date.add(~D[2000-01-01], 2)
~D[2000-01-03]
iex> Date.add(~N[2000-01-01 09:00:00], 2)
~D[2000-01-03]
iex> Date.add(~D[-0010-01-01], -2)
~D[-0011-12-30]