how to segment large matlab file using for loop

Dear all,

I have .mat file which contain 139x1000000 and its total time is 2:10:12. i want to break this in 5 minute of interval . One row contain 1000000 sample and time for row signal is alrady mention. The detail of file is attached . I want to break in every 5 minute of interval and all 5 minute interval should be save respectiely in a matrix.