The acquisition times are not saved in the NIfTI headers, but you can read them from the original DICOM. You can read the DICOM headers via:
P=spm_select(Inf,'.*','Select DICOM files');
H=spm_dicom_headers(P);
Then you can see what's in them by (for example):
H{1}
To see all the dates and times, you could try this:
for i=1:numel(H),
fprintf('%s\t %d-%d-%d\t%s\n', ...
H{i}.SeriesDescription,...
H{i}.SeriesNumber,...
H{i}.AcquisitionNumber,...
datestr(H{i}.AcquisitionDate...
+ H{i}.AcquisitionTime/(24*60*60),0))
end
Best regards,
-John