how to find time difference (in seconds) using matlab serial date number

Hello,

I have data obtained in matlab serial date number and I would like to convert them to seconds. Once I have them in seconds, I can calculate the time lapsed since the start of the measurement and plot it. Example of the data is:

[event_stamp, chan_mean] = [731895.4861, 0.696762; 731896.4097, 0.917459; 731896.5938, 0.678536; 731896.6771, 0.58941; 731953.4583, 1.09193]

Desired result [time[s], data] = [0, 0.696762; 1.2, 0.917459; 3.1, 0.678536; 4.5, 0.58941; 10, 1.09193]

thanks for your help!

Answer 1

[Walter Roberson]

lapsed_seconds = (YourData(:,1) - Yourdata(1,1)) * 24 * 60 * 60;

Answer 2

[Max Bernstein]

Thanks for your help, but dont I need to convert the serial date number to second first somehow?

[Guillaume]

Multiplying a date number by 24 (hours/day) x 60 (minutes/hour) x 60 (seconds/minute) will convert it to seconds.

[Walter Roberson]

You do not need to convert to seconds and then subtract. You can subtract and then convert to seconds.