See if something like this does what you want:
dnv = datenum([2016 01 00]) + cumsum(eomday(2016, 1:12)); % X-Axis Dates
loc1 = datenum([2016 01 01]) + randi(364, 1, 3); % Create Data
loc2 = datenum([2016 01 01]) + randi(364, 1, 5); % Create Data
loc3 = datenum([2016 01 01]) + randi(364, 1, 7); % Create Data
figure(1)
plot(loc1, 3*ones(size(loc1)), 'x')
hold on
plot(loc2, 2*ones(size(loc2)), 'x')
plot(loc3, 1*ones(size(loc3)), 'x')
hold off
grid
set(gca, 'XTick', dnv)
datetick('x', 'mmm', 'keepticks')
axis([xlim 0 4])
