You don't sepcify your file type. I'm going to assume a csv though this only matters for getting the data into MATLAB. My goal is to import it as a string. Modify as necessary for your file.
opts = detectImportOptions("timeData.csv","ReadVariableNames",false);
opts = setvartype(opts,1,"string");
data = readtable("timeData.csv",opts);
Once the data is read in as a table, convert it to a duration so that the time has units. As part of this, you can specify the input format.
tm = duration({data.Var1{:}},"InputFormat","mm:ss.SSSS")
You can view the seconds in two ways.
seconds(tm)
2. Specify the output format when converting to a duration.
tm = duration({data.Var1{:}},"InputFormat","mm:ss.SSSS",'Format',"s")
