You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: ncdateread.m
    path of file: ./repos/CDT/cdt
    
    the code of the file until where you have to start completion: function [dt, t, unit, refdate] = ncdateread(file, var, t)
%NCDATEREAD Reads da
    
function requires R2014b or later (relies on datetime and duration objects)');
end

% Check and parse input

if nargin > 2
    validateattributes(t, {'numeric'}, {}, 3);
else
    if iscell(file)
        t = cellfun(@(x) ncread(x, var), file, 'uni', 0);
        t = cat(1, t{:});
        file = file{1};
    else
        t = ncread(file, var);
    end