addDays

Adds days to a date-time.

Example:

    Vala.Time.DateTime dt = DateTime.of (2024, 2, 28, 0, 0, 0);
    assert (Dates.addDays (dt, 1).format ("%Y-%m-%d") == "2024-02-29");

Parameters:

t	date-time value.
days	days to add.

Returns:

shifted date-time.