See two lines with the comment " % CHANGED " and one line with the comment " % ADDED " to see how this answer differs from the previous one.
Also note that this can be used instead of the previous one by setting nThClosest to 1.
% Create two arrays of random dates (may contain repeated dates)
dates1 = datetime(2019,1,1)+days(sort(randi(364,1,100)));
dates2 = datetime(2018,12,28)+days(sort(randi(364,1,100)));
% Select the n_th closest date (positive integer)
nThClosest = 2; % ADDED
% Loop through the dates in date1
nearestIdx = nan(size(dates1)); % Pre allocation
dates2Temp = dates2; % Make a temp copy of dates2 for NaT replacement
for i = 1:numel(dates1)
[~, minKdurr] = mink(abs(dates2Temp - dates1(i)),nThClosest ); % CHANGED
nearestIdx(i) = minKdurr(end); % CHANGED
dates2Temp(nearestIdx(i)) = NaT; % replace that date with NaT
end
% Sanity check: all of the values in nearestIdx should be unique
assert(numel(unique(nearestIdx))==numel(dates1),'Sanity check failure: unique date matching error.')
% Match the dates (dates1 and dates2 must have same size)
m = [dates1.', dates2(nearestIdx).']
