Hi Rosanna, If your column data is in the following format ''Years.Months.Days Hours.Minutes.Seconds Data'', then the following code will work. I have created a xlsx file with data as you descrived above. At the end you can save date-time with your data column.
clear all
% Reading data from excel file
[a b]=xlsread('yourdata_according_to_question.xlsx')
% Reading Year, Month, Day
[y, m, d] = datevec(b(:,1),'dd.mm.yy')
% Reading only HOURS, Minutes and Seconds
[yyyy, mm, dd, HH, MM, SS] = datevec(b(:,2),'HH.MM.SS')
% Converting to Year, Month, Day, HOURS, Minutes and Seconds to charectors
y=num2str(y);
m=num2str(m);
d=num2str(d);
HH=num2str(HH);
MM=num2str(MM);
SS=num2str(SS);
% Adding all charector into single line
ymd=strcat(y,'-',m,'-',d);
hms=strcat(HH,':',MM,':',SS);
alltime=strcat(ymd,{' '},hms);
% Converting to datevec or datenum
alltime_dnum=datevec(alltime)
alltime_dvec=datenum(alltime_dnum)
